Question

Sin 9p\2 + cos 2p\2 + sin 13p\2 = ...?

Answer 1

Sin810+cos180+sin1170=sin90+cos180+sin90=1 - 1 + 1=1

Answer 2

Let's simplify the expression step by step:

1. sin(9π/2) = sin(4.5π) = sin(2π + 2.5π) = sin(2.5π) = -1 (since sin(π) = 0 and sin(2π) = 0, and sin(2.5π) = -1)

2. cos(2π/2) = cos(π) = -1 (since cos(π) = -1)

3. sin(13π/2) = sin(6.5π) = sin(2π + 4.5π) = sin(4.5π) = sin(2.5π) = -1

Now, let's add these values together:

-1 + (-1) + (-1) = -1 - 1 - 1 = -3

So, sin(9π/2) + cos(2π/2) + sin(13π/2) = -3.