Solve the equation 8x^3 -2x*2 -5x-1=0 Hence find the values of Theta< between 0 and 18 which satisfy the equation 8 tan^2 theta-2 tan theta -5=cot theta

Answer 1

(x-1)(2x+1)(4x+1) = 0
so, tanθ = 1 or -1/2 or -1/4

0 < θ < 18?

That's a weird domain. Anyway, you now have the starting values, so plug and chug.