(sint+cost)^2= ?
can any one me with this question

The answer to your question is: Yes.

Now, would you like to actually see the solution ?

First, multiply the quantity out:

(sin + cos)² = sin²(t) + cos²(t) + 2sin(t)cos(t)

You need to know:
==> sin²(any angle) + cos²(the same angle) = 1
==> 2sin(any angle)cos(the same angle) = sin(double the angle)

So the equation becomes:

(sin + cos)² = 1 + sin(2t)