Hi songoku, can you check my work below:
dy/dx=(dy/du)(du/dx)
=(u^2+5)^0.5 x -3
=3(u^2+5)^0.5
Question: why do I have to do this? i thought the question asked for the derivative of dy/dx and i substituted u into y and then found the derivative at x=-2.. isn't this what the question means?
Hi skeske1234
I'm not sure what you are doing on this part...
(u^2+5)^0.5 x -3 is not
Yes, you can subs. u into y. But :Question: why do I have to do this? i thought the question asked for the derivative of dy/dx and i substituted u into y and then found the derivative at x=-2.. isn't this what the question means?
First of all, not
Second, the formula above only applies for positive-integer power