Cube root means vectors addition class. You can do geometric construction to do that.
@Spandau-Filet9 күн бұрын
I just substituted numbers in my head. When I got to 2 and 4 it all fit…
@prime4239 күн бұрын
I always taught mathletes to try -1,0,1 immediately. This saves a lot of unnecessary time. If you solve a problem without explaining why you do something, it doesn't help novice problem solvers. Here one term is positive and the other is negative. What are the implications?
@pjaj439 күн бұрын
Far too complicated solution. 1) you can do it in your head. What two squares add up to 20? 16 and 4. 2) a=6-b (6-b)^2+b^2 = 20 36-12b+b^2+b^2 = 20 2b^2-12b+16 = 0 b= (12+/- sqrt(12^2-4*2*16))/2*2 b=(12+/- sqrt(16))/4 b=(12+/-4))/4 b=4 or 2 and since a=6-b it follows a= 2 or 4.
@edwardcullen17399 күн бұрын
I went for the similar approach, but factorised. Demonstrated approach probably "safer" if you don't have "nice" numbers.
@prime4239 күн бұрын
If x is a variable,dont use x for multiplication. Use a dot!!
@prime4239 күн бұрын
The solution is fine. But if this a teaching moment, the plan is the most important part of the solution!!
@RealQuInnMallory9 күн бұрын
4/ab^4 =1 (b ➖ 1a+1)
@RealQuInnMallory9 күн бұрын
(x ➖ 3x+3)
@shrikrishnagokhale355710 күн бұрын
My answer is 1+or- 5√5
@christopherrice89111 күн бұрын
Great we got 4 solutions for x. Now let's plug them back into the equation to see if they make the equation equal 0. All the solutions are too hard for me to plug them back in, will somebody please check them for me?(oh kudos to me for being the 1st one to leave a comment on here too!)
your square roots are dreadful. they look like 5 a square root symbol is formed from 3 straight lines
@user-fq6pe8jy3k13 күн бұрын
Nice question sir
@Joe-xo8ns13 күн бұрын
nice question which standard question
@KhanJan-th2gd14 күн бұрын
Great question and interesting sir, g❤❤❤
@user-fq6pe8jy3k14 күн бұрын
Interesting sir,g❤❤❤
@franciscook581915 күн бұрын
It's simpler to put it like this... The terms are grouped around (x+9)^4 so substitute t=x+9. Note that the +- 2 and +-1 cancel the odd terms so (t-2)^4+(t+2)^4 + (t-1)^4+(t+1)^4 + t^4=99 2*t^4+48*t^2+32 + 2*t^4+12*t^2+2 +t^4 = 99 simplifying ... 5t^4+60t^2-65=0 or (dividing by 5) t^4+12t^2+13=0 (t^2-1)(t^2+13)=0 t (=x+9) = ± 1 or ± i√13 so subtract 9 from the list to get x
@KhanJan-th2gd15 күн бұрын
Interesting❤❤❤
@freddyalvaradamaranon30415 күн бұрын
Muy interesante video, muchas gracias por compartir. Muy buena y didáctica explicación, mi hija y mi persona estamos muy agradecidos. 😊😊
@franciscook581916 күн бұрын
I liked your method but brute force and ignorance also works. Multiply both sides by (1+√x)^4 and expand using binomial (coeffs 1,4,6,4,1) => 82*√x^4-120*√x^3+108*√x^2-120*√x+82=16*√x^4+64*√x^3+96*√x^2+64*√x+16 66*√x^4-184*√x^3+12*√x^2-184*√x+66=0 33*x^2-92*x√x+6*x-92*√x+33=0 This is symmetrical so divide by x and group terms by x and √x 33(x+1/x)-92(√x+1/√x)+6=0 if we put s=(√x+1/√x) then s²=x+1/x + 2 => 33(s²-2)-92s+6=0 33s²-92s-60=0 (3s-10)(11s+6)=0 s=10/3 or -6/11 (but -6/11 gives imaginery roots) s=10/3=(√x+1/√x) multiply by 3√x 10√x=3x+3 3x-10√x+3=0 (3√x-1)(√x-3)=0 √x=1/3 or 3 x=1/9 or 9
@pjaj4316 күн бұрын
Let x=sqrt(a) then sqrt(-a) = ix equation becomes x + ix = 32 x(1+i) = 32 x = 32/(1+i) multiply top and bottom by (1-i) x = 32(1-i)/(1+i)(1-i) x = 32(1-i)/2 = 16(1-i) square both sides a = x^2 = 256(1 - 2i - 1) = -512i
@user-fq6pe8jy3k16 күн бұрын
Interesting question ❤❤❤❤
@zoubirbahfir265416 күн бұрын
we mutiply the numerator and denominator by √x+2 we will have √((√x+2)²/(x+4)) = √x+2 so √(√x+2)²/√(x-4) = √x+2 and then √x+2/√(x-4) = √x+2 we simplify 1/√(x-4) = 1 ==> √(x-4) = 1 x-4 = 1 ==> x= 5
@robertliu317617 күн бұрын
let sqrt(sqrt(x)+11) = t, then sqrt(x) = t^-11, then t+sqrt(t^2-11) = 11, then sqrt(t^2-11) = 11-t, then t^2-11=11^2-22t+t^2, then t=6. Then sqrt(x)=25 then x = 625
@guyhoghton39917 күн бұрын
Nice, but I think this way is simpler here. Let _a = √x + 2, b = √x - 2_ _a ≥ 2_ and _ab = x - 4_ The equation is _√(a/b) = a_ Squaring: _a/b = a²_ ⇒ _a(ab - 1) = 0_ ⇒ _a = 0 (rejected, a ≥ 2) or ab = 1_ ∴ _ab = x - 4 = 1_ ⇒ *_x = 5_*
@KhanJan-th2gd17 күн бұрын
Interesting question❤❤
@user-fq6pe8jy3k17 күн бұрын
V nice sir
@mircoceccarelli668918 күн бұрын
🤪👍👍😁🤪👋
@KhanJan-th2gd18 күн бұрын
Nice
@user-fq6pe8jy3k18 күн бұрын
Interesting question ❤❤❤
@pietergeerkens632420 күн бұрын
The second half is unnecessary on this problem. We know a + b = -2 ab = -2 so by Viete we can solve for a and b as a = 1 + sqrt(3), b = 1 - sqrt(3) Then the binomial theorem allows us to show that x = 1 + 3 * 21 + 9 * 35 + 27 * 7 = 1 + 63 + 315 + 189 = 568