Question

What is the period of cos ( 4x + 5)​

Answer 1

Answer:

If a function f(x) is periodic with T , then the function f(ax+b) is periodic with

∣a∣

T

cos(x) is periodic with 2π

So, cos(

5

4x+9

)=cos(

5

4x

+

5

9

) is periodic with

5

4

2π

=

4

5

×2π

=

2

5π