Homework Help: math

Posted by raj on Monday, October 29, 2007 at 10:50am.

Solve the following equations giving any roots in terms of pi in the .......?
interval -2pi ≤ 0 ≤ 2pi.

a) 2cos²Θ + sin²Θ = 0

b) 2cos²Θ + sin²Θ = 1

c) 2cos²Θ + sin²Θ = 2

math - drwls, Monday, October 29, 2007 at 12:16pm
First convert cos^2 theta to 1 - sin^2 theta. Then treat sin^2 as a new variable x and solve for that using quadratic equation procedures.
math - Reiny, Monday, October 29, 2007 at 1:45pm
I will do the last one for you

2cos²Θ + sin²Θ = 2
2cos²Θ + 1 - cos²Θ = 2
cos²Θ = 1
cosΘ = ±1

in degrees, Θ = 0º or 180º or 360º
in radians: Θ = 0 pi or 2pi

Answer this Question

Related Questions

Trigonometry - 1. Find the exact value of the following (Think identity) Cos(2 ...
Calculus - Find the interval(s) where the function is increasing where and it is...
math-Trig - 1. Write the algebraic expression which shows Cos((ArcSin(4/X)), 2...
Math - solve sin(2θ)+1=0 on the interval 0≤θ&#...
Math-Trig - Trig Questions- 1. Write the algebraic expression which shows Cos((...
trigonometry - solve sin(2θ)+1=0 on the interval 0≤&#952...
TRIGONOMETRY HELP - Prove that: cos²Θ - sin²Θ = 2cos...
Math/Trigonometry - 1. Solve: 2 cos² x - 3 cos x + 1 = 0 for 0 ≤ ...
Trig - check my answers plz! - 1. (P -15/17, -8/17) is found on the unit circle...
Math/Trigonometry - 1. Solve: 2 cos² x - 3 cos x + 1 = 0 for 0 ≤ ...

For Further Reading

First Name:
School Subject:
Answer: