Posted by Jovante on .
y=cos(square root of 4t+12)

Calculus 
IVR,
dy/dt=sin(square root of 4t+12)*d/dx(sqare root of 4t+12)
=sin(sqare root of 4t+12)*1/2*sqare root of 4t+12 * 4
=sin (sqare root of 4t+12)* 2/sqare root of 4t+12