Question

Find the local maxima and local minima for thefunction f(x) = sin (7x) –5.

Answer 1

f(x) = sin (7x) –5

Differentiating,

f'(x) =7cos(7x)

now,equaling it to zero,we get,

7cos(7x)=0

or, cos(7x)=0

or, 7x=π/2

or, x=π/14

the critical coordinat of x is π/14.

now, f(π/14)=sin (7 *(π/14)) –5=sin(π/2)-5=1-5=-4.