Equation

• Mar 11th 2011, 11:19 AM
Critter314
Equation
How to prove?
$cos 2x + cos x = sin^2 x$
All Ive got so far is $cos^2 x - sin^2 x + cos x = sin^2 x$
• Mar 11th 2011, 11:23 AM
emakarov
Let's see, cos(2 * 0) + cos(0) = 2. Hmm...
• Mar 11th 2011, 11:36 AM
TheChaz
Now substitute $\displaystyle \sin^2{x} = 1 - \cos^2{x}$ to get a quadratic equation in $\displaystyle \cos{x}$, which you will be able to solve.
The text contains a mathematical question in the form of an equation to prove, and it also includes a suggestion for solving the equation.
single_question_with_answer
Given a text passage, determine:
    1. If it contains a mathematical question (including word problems or calculations)
    2. If an answer to that mathematical question is provided in the text

First, describe the content structure you found in 1-2 sentences.

Then provide your analysis in the following format:
TYPE: <one of the following values>
- NO_QUESTION
- SINGLE_QUESTION
- SINGLE_QUESTION_WITH_ANSWER
- MULTIPLE_QUESTIONS
- MULTIPLE_QUESTIONS_WITH_ANSWERS
system
Equation

• Mar 11th 2011, 11:19 AM
Critter314
Equation
How to prove?
$cos 2x + cos x = sin^2 x$
All Ive got so far is $cos^2 x - sin^2 x + cos x = sin^2 x$
• Mar 11th 2011, 11:23 AM
emakarov
Let's see, cos(2 * 0) + cos(0) = 2. Hmm...
• Mar 11th 2011, 11:36 AM
TheChaz
Now substitute $\displaystyle \sin^2{x} = 1 - \cos^2{x}$ to get a quadratic equation in $\displaystyle \cos{x}$, which you will be able to solve.
user
The text contains a mathematical question in the form of an equation to prove, and it also includes a suggestion for solving the equation.

TYPE: SINGLE_QUESTION_WITH_ANSWER