Which equation is not an identity?

tan (-t) = - tan t

tan t (csc t + cot t) = sec t + 1

sin tcot t = cos t

cos2t - sin2t = - 1

Solve the equation for y. Then find the value of y for each value of x. 2x - 5y = 17; x = - 3, 0, 3 Solve the equation for y

The cross-sectional area of a water pipe is 5058 square inches. to the nearest tenth, what is the diameter of the pipe in inches?

What is the range of (3.2,-3)

For the given expression, use the Associative Property of Multiplication to enter an equivalent expression. (ab) c = ?

At a certain college, 30% of the students major in engineering, 20% play club sports, and 10% both major in engineering and play club sports. A student is selected at random. What is the probability that the student is majoring in engineering?

Katherine drove 112 miles in 4 hours. If she continued at the same rate, how far would she travel in 15 hours?

X2 = x + 12 Solve this

Mary has a small round mirror in her purse. If the mirror is 4 inches in diameter, what is the area of the mirrored surface?

Kelly is 15 years older than frank. In 2 years time, she will be 4 times as old as him. Find their present ages

An audio/video equipment discount store has 36 salespeople. Daily dollar sales for individual sellers enployed by the store has a normal distribution with a mean of $2000 and a standard deviation of $300.