Sin(90 + α) = Cos α But cos is negative in Q2. (90 + α) is going to Q2. So why Cos α is not negative in that equation?

In the pendulum formula t=2pi. read the problem on the picture ! ; $; $; ! ; ! ; ! ; )$; ! ; ! ; ! ; $; $; $! ; ! ; ); $; $$

Let the mean of the population be 38 instances of from 6" - 9" hatchings per nest, and let the standard deviation of the mean be 3. what sample mean would have a confidence level of 95% or a 2.5% margin of error?

On a architect's drawing of a house, 1 inche representa 1.5