Question

find the solutions of the equation... tan^2(x)+tanx-1=0 in the interval (-pi/2)(pi/2).. i have the answers in the book which are...-1.02 and 0.55.. just dont know how to get there! thanks!!

Answer 1

are you allowed a calculator?

Answer 2

let me check

Answer 3

it doesnt say not to!!!

Answer 4

it says give ur answer totwo decimal places so im guessing i can use it

Answer 5

in that case let y= tan(x)
your equation is
y^2 +y -1 = 0

find y, using the quadratic formula

Answer 6

ok hold on

Answer 7

once you find the two values for y, you have
tan x = y
take the inverse tangent of both sides to get
x = arctan(y)
be sure your calculator is in radian mode (or if in degrees, multiply by pi/180 to change your answer to radians)