Prove this

1-tan^2x/1+tan^2x=cos^2x-sin^2x

Question 13 of 451 pointwhich statement correctly describes the inverse of the following function? a. it is negative.b. it is a horizontal shift.c. it is not a function.d. it is a function. give an explanation as to why you chose that answer. (i think its either a or d.)

The price of an item has been reduced by 30%. the original price was $30. what is the price of the item now ?

What are the solutions of the system? solve by graphing. y = x^2 + 3x + 2 y = 2x + 2