Question

What is the derivative of `y = x [sec (3 - 8x)]`?

Answer 1

`1/cos(3-8x)(1-8xtan(3-8x))`

Explanation:

`y = x [sec (3 - 8x)]=x/cos(3-8x)`
`y'=1/cos(3-8x)-8*sin(3-8x)*x/(cos(3-8x)^2)`
`=1/cos(3-8x)(1-8xtan(3-8x))`