Find the derivative of y.
-$$y = \cosh x ^ { 7 }$$
A) $\sinh x ^ { 7 }$
B) $- \sinh x ^ { 7 }$
C) $7 x ^ { 6 } \sinh x ^ { 7 }$
D) $- 7 x ^ { 6 } \sinh x ^ { 7 }$

Question

Quizplus · Accepted Answer

We use the chain rule here. Let u = cosh x. Then y = u^7. 
Therefore, dy/dx = 7u^6 * du/dx. 
But du/dx = sinh x. 
So, dy/dx = 7 cosh^6 x * sinh x = 7x^6 sinh x^7. Thus, the correct option is (C).

Find the Derivative of Y y=cosh⁡x7y = \cosh x ^ { 7 }y=coshx7

Find the Derivative of Y $y = \cosh x ^ { 7 }$