Can someone me?

verify each trigonometric equation by substituting identities to match the right hand side of the equation to the left hand side of the equation.

a. (sin x)(tan x cos x - cot x cos x) = 1 - 2 cos2x

b. 1 + sec2x sin2x = sec2x

c. [(sin(x))/(1-cos(x))]+[(sin(x))/(1+ cos(x))]=2csc(x)

d. - tan2x + sec2x = 1

Abank manager wants to encourage new customers to open accounts with principals of at least $2 comma 500. he decides to make a poster advertising a simple interest rate of 3%. what must the principal be if the bank manager also wants to advertise that one can earn $10 the first month? can the poster correctly say, "open an account of $2 comma 500 and earn at least $10 interest in 1 month! "?