@ 2:40 / 10:09 (x - 3)² - 7² = 0 (x - 3)² = 7² x - 3 = ± 7 x = 3 ± 7 → x = 10 → x = - 4 (x - 3)² + 7² = 0 (x - 3)² = - 7² x - 3 = 7².i² x = 3 ± 7i → x = 3 + 7i → x = 3 - 7i
@brianwade41792 сағат бұрын
You went way off the rails at 3:03. There is a much simpler solution than what you did. You should have factored [(x-3)^2 - 7^2] as difference of two squares: (x-3+7)(x-3-7). This would have immediately given you roots {-4,10}. Similarly you should have rewritten [(x-3)^2 + 7^2] as [(x-3)^2 - (-7^2))], also a difference of two squares, and then factored it as (x-3+7i)(x-3-7i). This would have immediately given you roots {3-7i,3+7i}.
@aravindhnagarathinam4 сағат бұрын
👍👍👍
@nugrohofadill13 сағат бұрын
Great
@prollysine22 сағат бұрын
let u=3^x , u^3+u^2+u-14=0 , (u-2)(u^2+3u+7)=0 , 3^x=2 , x=log2/log3 , test , 3^x+9^x+27^n,x=2+4+8 , --> 14 , OK , 1 -2 3 -6 7 -14
@davidseed293923 сағат бұрын
if you divide through by x^5 and substitute a=x+1/x then we get (a^2-1)/(a+1)=3 so a-1=3 a=4 x^2-4x-1=0 x=2+-ζ3
@mirandak327320 сағат бұрын
There are seven possible roots. The two real ones this method gets plus three superfluous ones of 0 that are rejected due to the domain of x and two complex ones of: negative 1/2 plus or minus 1/2i * sgrt(3) First cross multiply, then move all to the left, then factor out x^3, then divide by x^2, then make x^2 * 1/x^2 into (x + 1/x)^2 -2, then substitute a for x + 1/x. a solves for both 4 and for -1, giving us the two real roots and the two complex roots of x.
@eng95418 сағат бұрын
@@mirandak3273 congrats!
@SHIPSPROWКүн бұрын
X-3=4
@SALogics23 сағат бұрын
And what is x? ❤
@SHIPSPROW21 сағат бұрын
Don't know. Too difficult.
@اسماعیلخسروی-خ6ظКүн бұрын
❤❤❤
@SALogics23 сағат бұрын
Thanks for liking! ❤
@patk5724Күн бұрын
There is also another result such as: x = 144 and y = 16(log6/log2)^2 You can proof check it to confirm result etc...
I think this ways is a bit easier: (x - 3)^6 = 4^6 (x - 3)^(3 * 2) = 4^(3 * 2) ([x - 3]^3)^2 = (4^3)^2 Let a = (x - 3)^3, and b = 4^3 a^2 = b^2 a^2 - b^2 = b^2 - b^2 a^2 - b^2 = 0 (a - b)(a + b) = 0 ([x - 3]^3 - 4^3)([x - 3]^2 + 4^3) = 0 Let a = x - 3, and b = 4 (a^3 - b3)(a^3 - b^3) = 0 (a - b)(a^2 + ab + b^2)(a + b)(a^2 - ab + b^2) = 0 (a - b)(1 * a^2 + b * a + b^2)(a + b)(1 * a^2 - b * a + * b^2) = 0 Suppose a - b = 0 a - b = 0 Remember, a = x - 3, and b = 4 (x - 3) - 4 = 0 x - 3 - 4 = 0 x - 7 = 0 x - 7 + 7 = 0 + 7 x = 7 Suppose 1 * a^2 + b * a + b^2 = 0 1 * a^2 + b * a + b^2 = 0 a = (-b +/- sqrt[b^2 - 4 * 1 * b^2]) / (2 * 1) a = (-b +/- sqrt[1 * b^2 - 4 * b^2]) / (2) a = (-b +/- sqrt[(1 - 4) * b^2]) / 2 a = (-b +/- sqrt[(-3) * b^2]) / 2 a = (-b +/- sqrt[(-1) * 3 * b^2]) / 2 a = (-b +/- sqrt[-1] * sqrt[3] * sqrt[b^2]) / 2 a = (-b +/- i * sqrt[3] * b) / 2 a = b * (-1 +/- i * sqrt[3] * 1) / 2 Remember, a = x - 3, and b = 4 x - 3 = 4 * (-1 +/- Ii* sqrt[3] * 1) / 2 x - 3 = 2 * (-1 +/- i * sqrt[3]) x - 3 = -2 +/- i* 2 * sqrt(3) x - 3 + 3 = 3 - 2 +/- i * 2 * sqrt(3) x = 1 +/- i * 2 * sqrt(3) x = 1 + i * 2 * sqrt(3), or x = 1 - i * 2 * sqrt(3) Suppose a + b = 0 a + b = 0 Remember, a = x - 3, and b = 4 (x - 3) + 4 = 0 x - 3 + 4 = 0 x + 1 = 0 x + 1 - 1 = 0 - 1 x = 1 Suppose 1 * a^2 - b * a + * b^2 = 0 1 * a^2 - b * a + * b^2 = 0 a = (-[-b] +/- sqrt[(-b)^2 - 4 * 1 * b^2]) / (2 * 1) a = (b +/- sqrt[1 * b^2 - 4 * b^2]) / (2) a = (b +/- sqrt[(1 - 4) * b^2]) / 2 a = (b +/- sqrt[(-3) * b^2]) / 2 a = (b +/- sqrt[(-1) * 3 * b^2]) / 2 a = (b +/- sqrt[-1] * sqrt[3] *sqrt[b^2]) / 2 a = (b +/- i * sqrt[3] * b) / 2 a = b * (1 +/- i * sqrt[3] * 1) / 2 Remember, a = x - 3, and b = 4 x - 3 = 4 * (1 +/- i * sqrt[3]) / 2 x - 3 = 2 * (1 +/- i * sqrt[3]) x - 3 = 2 +/- i * 2 *sqrt(3) x - 3 + 3 = 3 + 2 +/- i * 2 *sqrt(3) x = 5 +/- i * 2 *sqrt(3) x = 5 + i * 2 *sqrt(3), or x = 5 - i* 2 * sqrt(3) x1 = 7 x2 = 1 + i * 2 * sqrt(3) x3 = 1 - i * 2 * sqrt(3) x4 = 1 x5 = 5 + i * 2 *sqrt(3) x6 = 5 - i * 2 *sqrt(3)
@SALogics23 сағат бұрын
Very nice! ❤
@AhmedanterElsayedКүн бұрын
(x - 3 )6 = 46 solution (x - 3 )6 = 46 dividing both sides of the equation by 46 ((x-3)/4)6 = 1 By taking the sixth root of the two sides of the equation (x-3)/4 = √(6&1) = 1 1/6 1 = cos 0° + i sin 0° Then (x-3)/4 = (cos 0° + i sin 0°)1/6 by applying (x-3)/4 = (cos 0° + i sin 0°)=1 Then x =7 (x-3)/4 = (cos (0+1×360)/6° + i sin (0+1×360)/6°)= 1/2 + √3/2 i Then x = 5+2 √3 i (x-3)/4 = (cos (0+2×360)/6° + i sin (0+2×360)/6°)= (-1)/2 + √3/2 i Then x = 1+2 √3 i (x-3)/4 = (cos (0+3×360)/6° + i sin (0+3×360)/6°)= -1 Then x = -1 (x-3)/4 = (cos (0+4×360)/6° + i sin (0+4×360)/6°)= (-1)/2 - √3/2 i Then x = 1 - 2 √3 i (x-3)/4 = (cos (0+5×360)/6° + i sin (0+5×360)/6°) = 1/2 - √3/2 i Then x = 5 - 2 √3 i
@SALogics23 сағат бұрын
Very nice! ❤
@wes9627Күн бұрын
Substitute x=y-10 into the given equation and rearrange to 2*4(y^3+y)-544=0 or y^3+y-68=0 yields y=4 by inspection. Divide by (y-4): y^2+4y+17=0 yields y=(-4±i2√13)/2=-2±i√13. Then x=y-10=4-10=-6 or -2±i√13-10=-12±i√13
@SALogics23 сағат бұрын
Very nice! ❤
@GauravGupta-ut7kvКүн бұрын
Way of explanation is very good 👌
@SALogics23 сағат бұрын
Thank you so much! ❤
@aravindhnagarathinamКүн бұрын
👍👍👍👍
@SALogics23 сағат бұрын
Thanks for liking! ❤
@aravindhnagarathinam2 күн бұрын
👍👍👍
@SALogicsКүн бұрын
Thanks for liking! ❤
@davidseed2939Күн бұрын
i think ive seen this problem before. set a=(x-3)/4 a⁶=1 a=1^(1/6) the 6 roots of 1 are uniformly distibuted on the unit circle on the complex plane(Argand diagram) so they are spaced at 60 degrees apart so the real roots are a=+-1 The first complex root is at cos60+isin60=(1+iζ3)/2 all 4 complex roots can be written as a= (+-1+-ζ3)/2 we can solve for x by substituting a=(x-3)/4 or x=3+4a eg x=7,-1 ...
4^(x+1)-4^(x-1)=5 4^2*4^(x-1)-4^(x-1)=5 4^(x-1)*(4^2-1)=5 You can exclude 4^(x+1), 4^x, 4^(x-1).... and even 4^(x+10) but then it complicates the numerical calculations. First I chose 4^(x-1). For 4^(x+10) showing below. 4^(x-1)*(16-1)=5 4^(x-1)*(15)=5 4^(x-1)=5/15=1/3 |log() both sides The essence of the solution can be applied after various transformations. log{4^(x-1)}=log{3^(-1)} (x-1)*log(4)=-log(3) x-1=-log(3)/log(4) x=1-log(3)/log(4) 4^(x+1)-4^(x-1)=5 4*4^x-(1/4)*4^x=5 4^x*(4-1/4)=5 4^x*(15/4)=5 4^x=20/15 |log() x*log(4)=log(20/15) x=log(4/3)/log(4) x=1-log(3)/log(4) 4^(x+1)-4^(x-1)=5 4^(x+10)*4^(-9)-4^(x+10)*4^(-11)=5 4^(x+10)*{4^(-9)-4^(-11)}=5 4^(x+10)=5/{4^(-9)-4^(-11)} | log() both sides (x+10)*log(4)=log[5/{4^(-9)-4^(-11)}] (x+10)=log[5/{4^(-9)-4^(-11)}]/log(4) ... In the end you will get the same answer but you have more calculations on the right side of the equation (x+10)=log[5/{4^(-11)*(4^2-1}]/log(4) (x+10)=log[5/{4^(-11)*(15}]/log(4) (x+10)=[log(5)+11*log(4)-log(15)]/log(4) (x+10)=[log(5)-log(15)+11*log(4)]/log(4) x+10=[log(1/3)+11*log(4)]/log(4) x+10=11-log(3)/log(4) x=1-log(3)/log(4)
Aprendi propiedades de los logaritmos que no conocia. 👏👏👏👏
@SALogics3 күн бұрын
sigue aprendiendo! ❤
@mariaestersimon31073 күн бұрын
Muy interesante!
@SALogics3 күн бұрын
gracias por gustar! ❤
@aravindhnagarathinam4 күн бұрын
👍👍👍
@SALogics3 күн бұрын
Thanks for liking ❤
@فیروزاهنگری4 күн бұрын
let 3^x=y , y+x=30 , x=30-y 3^x=y and x=30-y then 3^(30-y)=y [3^(30-y)=y]^1/(30-y) 3=y^1/(30-y) , 27^1/3=y^1/(30-y) 27^1/(30-27)=y^1/(30-y) result y=27 and y=3^x , 27=3^x 3^3=3^x ,. x=3
@SALogics3 күн бұрын
Very nice! ❤
@aravindhnagarathinam4 күн бұрын
👍👍👍
@SALogics3 күн бұрын
Thank you so much! ❤
@SamudraNeelKar4 күн бұрын
Also x=1 is a solution
@narayang12454 күн бұрын
Wrong, 12 will be the answer, not 5
@SALogics3 күн бұрын
If x = 1 then LHS will be 15 that is not equal to RHS ❤
@ajitandyokothakur71914 күн бұрын
You could easily do it as follows: 4^(x+1) - 4^(x-1) = 5; or, 4^x *4 - 4^x *4^(-1) = 5; or, (4^x)(4 - 1/4) =5; or, (4^x)*(15/4). Now you can follow as you did. Dr. Ajit Thakur (USA).