Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

Pages: **1**

**fusilli_jerry89****Member**- Registered: 2006-06-23
- Posts: 86

√ 2 sin²-cos=0

Offline

**Zhylliolom****Real Member**- Registered: 2005-09-05
- Posts: 412

Offline

**fusilli_jerry89****Member**- Registered: 2006-06-23
- Posts: 86

can you please explain how you got from this to this:

2cos²+cos-2 to cos = -1±√1-(4)(2)(-2)/2(2)

Offline

**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,638

That would be the Quadratic Equation

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

Offline

**Zhylliolom****Real Member**- Registered: 2005-09-05
- Posts: 412

Yes, it is the quadratic formula. If we let *x* = cos *θ*, then

which may be solved by means of the quadratic formula.

Offline

**fusilli_jerry89****Member**- Registered: 2006-06-23
- Posts: 86

Zhylliolom wrote:

Yes, it is the quadratic formula. If we let

x= cosθ, thenwhich may be solved by means of the quadratic formula.

Oh yeah, how stupid of me

Offline

Pages: **1**