How would you do number 6?
also it says standard deviation of 100

What makes a trapezoid an isosceles trapezoid?

Use the squared identities to simplify sin^2x cos^2x

One cell phone plan charges $20 per month plus $0.15 per minute used. a second cell phone plan charges $35 per month plus $0.10 per minute used. write and solve an equation to find the number of minutes you must talk to have the same cost for both calling plans.