Solve for -pi < x < pi: tanx = 4cotx + 3

tanx = 4cotx + 3  - Multiply through by tan to form a quadratic. tan^2x = 4 + 3tanx - Simplify by allowing y to equal tanx. y^2 = 4 + 3y - Rearange to standard quadratic form. y^2 - 3y -4 = 0 - Factorise. (y - 4)(y + 1) = 0 Therefore y = 4 and y = -1 Substitute y=tanx to solve for x: y = 4 tanx = 4 x = tan-14 x= 1.326 (3d.p.) tanx = -1 x = tan-1 -1 x = -pi/4

ZL

Related Maths A Level answers

All answers ▸

log3 (9y + b) – log3 (2y – b) = 2, Find y in terms of b.


A mass of 3kg rests on a rough plane inclined at 60 degrees to the horizontal. The coefficient of friction is 1/5. Find the force P acting parallel to the plane applied to the mass, in order to just prevent motion down the plane.


Consider f(x)=x/(x^2+1). Find the derivative f'(x)


Find ∫ x^2(ln(4x))dx