Use the fugue to find the exact values of sin 2u, cos 2u, and tan 2u

Sin 2u= 2sin u*cos u=2*(-3/5)*4/5=-24/25
cos 2u= 1-2sin^2(u)=1-2*(9/25)=1-18/25=7/25
tan 2u= sin/cos=-24/7
These are the correct answers.

Vertical stretch occurs when a function value is multiplied by a number greater than 1.

For a function f(x), m*f(x) stretches f(x) in y direction if m is greater than 1. 

From the given options we can see only A option lists such a case where an exponential function is being multiplied by a number greater than 1.

So, the answer to this question is A