# Math Help - Quadratic Equation: please sove

Solve the quadratic equation of x

(sin(2a)).x2 - 2.x.(sin(a)+cos(a)) +2 =0

2. ## Re: Quadratic Equation: please sove

Rewrite $\sin {2a}$ as $2 \sin a \cos a$ and divide everything by 2:

$(\sin a \cos a )x^2 - (\sin a + \cos a)x + 1 = 0$

Apparently this factors to

$(x \sin a - 1)(x \cos a - 1) = 0$.

Solve for x.

3. ## Re: Quadratic Equation: please sove

Thanks for it Richard. I appreciate it but I still don't get it. Can you explain it further?

4. ## Re: Quadratic Equation: please sove

What step don't you get?

5. ## Re: Quadratic Equation: please sove

In the substitution.

6. ## Re: Quadratic Equation: please sove

Trig identity, $\sin 2a = 2 \sin a \cos a$ for all $a$.

Thanks!