Solve.. answer In radians!

tan²x-2 tanx-3=0

1. according to the internal revenue service, the mean tax refund for the year 2007 was $2,708. assume the standard deviation is $650 and that the amounts refunded follow a normal probability distribution. a. what percent of the refunds are more than $3,000? b. what percent of the refunds are more than $3,000 but less than $4,000? c. what percent of the refunds are less than $2,000?

Find the value of x to the nearest tenth.

3. simplify. 312⋅312 4. rewrite n√xm using a rational expression.