Posted by lee pearce on .
function y=42sin(2t+pi/2), where t is measured in radians. choose one option which gives the value of the function when t=pi radians.
a)0 b)1 c)2 d)4 e)pi/4 e)pi/4 f)pi/2 g)pi h)2pi

Trigonometry 
Reiny,
y=42sin(2t+pi/2) , when t= π
y = 4  2sin(2π + π/2) = 4  2sin(5π/2)
= 4  2sin(π/2) , since π/2 and 5π/2 are coterminal angles.
= 4  2
= 2 
Trigonometry 
lee pearce,
Cheers Reiny