Solve Trig Equation: 1+cos(180+2u) let 90+u be f

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In summary, a trigonometric equation is an equation that involves trigonometric functions and can be solved by manipulating the equation and using inverse trigonometric functions. The purpose of solving a trigonometric equation is to find the value of a variable in an equation involving trigonometric functions. The given equation is asking us to find the value of f in terms of u and the steps to solve it involve using various trigonometric identities.
  • #1
UnD
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Lol this one troubling me badly.

Simplify 1+cos(180+2u) let 90+u be f
1+cos(2f)
then 1+ cos^2 (f) - sin^2 (f)
umm then it's 2 Cos^2 (f)

lol I'm a bit lost.

what do you after that lol, or do you do it an easier way .Thanks in advance :cry:
 
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  • #2
Easier way. Dont forget that cos(180+X) = -cos(X)
Therefrore cos(180+2u) = -cos(2u). Can u go from there?
 
  • #3
Ah yea. lol thanks very much. I can.
 

1. What is a trigonometric equation?

A trigonometric equation is an equation that involves trigonometric functions, such as sine, cosine, and tangent. These equations often involve angles and can be solved by using trigonometric identities and properties.

2. How do you solve a trigonometric equation?

To solve a trigonometric equation, you must use trigonometric identities and properties to manipulate the equation into a form where the variable can be isolated. Then, you can use inverse trigonometric functions to solve for the variable.

3. What is the purpose of solving a trigonometric equation?

Solving a trigonometric equation allows us to find the value of a variable in an equation involving trigonometric functions. This is useful in many fields, including physics, engineering, and mathematics.

4. What is the given equation asking us to solve?

The given equation, 1+cos(180+2u) let 90+u be f, is asking us to find the value of f in terms of u. This can be done by using the trigonometric identities 1+cos(x) = 2cos^2(x/2) and cos(180+x) = -cos(x).

5. Can you explain the steps to solve the given trigonometric equation?

To solve the given equation, we first use the identity 1+cos(x) = 2cos^2(x/2) to rewrite the equation as 2cos^2(90+u/2). Then, we use the identity cos(180+x) = -cos(x) to rewrite the equation as -2cos^2(u/2). Next, we use the fact that let 90+u be f to replace u in the equation, giving us -2cos^2(f/2). Finally, we use the identity cos^2(x) = (1+cos(2x))/2 to rewrite the equation as -(1+cos(f)). Therefore, we have solved the equation and found the value of f to be -1.

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