Stanford University Admission Test Tricks ! |✍️🖋️📘💙

[@Taric25]

That W function was completely useless. -6^-5 = (-x-4)6^(-x-4)=(-6)(6^-6). That automatically means -6 = -x-4. You went through all those extra steps for nothing.

[@AlbertoDiJanni]

X=2 in just 3 seconds.

[@2012tulio]

2 is not the only solution it can be -3.99 also by Lambert

[@MrMackxl65]

The 'eye' test does yield x = 2 immediately. The other value of x has to be analytically deduced.

[@TheNizzer]

Don’t worry if you can’t understand this prior to university entrance. It’s not on the syllabus until undergraduate level. It did appear on a Cambridge STEP paper, but no prior knowledge is required. DESMOS is useful to see the function.

[@Taric25]

That W function was completely useless. -6^-5 = (-x-4)6^(-x-4)=(-6)(6^-6). That automatically means -6 = -x-4. This video went through all those extra steps for nothing. The negative answer requires a calculator anyway, which you can use to find where the two lines intersect very easily.

[@2012tulio]

This has 2 solutions X= -3.99 by Lambert and X= 2 by guess and check

[@mpraonelavellinelavelli7096]

Very lengthy method sir

[@superacademy247]

I appreciate your feedback! 🔥💪

[@harisvictory2712]

X = 2 as my intuitive way.

[@07Pietruszka1957]

6^x=6*x+24 6^x=6*(x+4) || *6^4 6^x*6^4=6^1*6^4*(x+4) 6^(x+4)=6^5**(x+4) || /{6^5*6^(x=4)} 6^(-5)=6^(-x-4)*(x+4) || *(-1) -6^(-5)=6^(-x-4)*(-x-4) -6^(-5)=exp{ln[6^(-x-4)]}*(-x-4) || *ln(6) -6^(-5)*ln(6)=exp{(-x-4)*ln[6]}*ln(6)*(-x-4) || W() ....and so on

[@prollysine]

1/6=(x+4)/6^x , /*1/6^4 , 1/6^5=(x+4)*e^(-ln6*(x+4)) , /*-ln6 , (-ln6)/6^5*(6/6)=-ln6(x+4)*e^(-ln6*(x+4)) , , W(-6*ln6*e^(-6*ln6)=W(-ln6(x+4)*e^(-ln6*(x+4))) , -6*ln6= -ln6(x+4) , 6=x+4 , x=2 , test , 36=36 , OK ,

[@2012tulio]

2 is not the only solution, it can be -3.99 also by Lambert

[@prollysine]

@@2012tulio 6^(-3.99)=7.86*10^(-4) , 6*(-3.99)+24=0.6 , not the same , -3.99 is a not a solution ,

[@2012tulio]

​@@prollysine please double check with Wolfram alpha and see the graph

[@prollysine]

@@2012tulio So why does the calculation give a difference?

[@2012tulio]

​@@prollysineit's 0.06 not 0.6