So here is how to simplify the given value above.
We can rewrite the given equation as: sin(pi/2-y)/cos(y)
Next, let's use the basic formula for sin(a-b) as=sina*cosb-cosa*sinb.
Using that, we will get this result:
(sin(90)cosy-cos(90)siny)/cosy
after substituting the value of sin(90)=1 and cos(90)=0,
the final answer that we will get is cosy/cosy=1 ans.
sec(y)sin(π/2−y)=1/cos(y)×cos(y)=1
Hope this answer helps.