Originally Posted by

**Gayelle** Please help me solve this Trig. equation :

tan(x) + 3cot(x) = 5sec(x)

so far I have arrived at

(tan(x))^{2} = (0.3334)^{1/2}

tan(x) = 0.5774 & -0.5774

x = 30^{0} & -30^{0}

However the solution states x = 30^{0} as the principal solution, only. Which is correct since when x = -30^{0} is substituted into the original equation the LHS and RHS of the equation

are numerically equal but opposite in sign.

That said my question is, what am I missing? How am I supposed to ascertain which is the correct value of x (as the square root of a number has both -ve and +ve solutions) without substituting x back into the original equation. Or is it expected that i do exactly that, substitute back into the equation for all solutions derived directly from the square root of number.

Ooh one other thing what do you guys use to input mathematical equations or formulea more efficiently on this board?

Thank You.