All Precalculus Resources
Example Questions
Example Question #1 : Proving Trig Identities
Simplify .
This expression is a trigonometric identity:
Example Question #3 : Prove Trigonometric Identities
Simplify
Factor out 2 from the expression:
Then use the trigonometric identities and to rewrite the fractions:
Finally, use the trigonometric identity to simplify:
Example Question #257 : Pre Calculus
Simplify
Factor out the common from the expression:
Next, use the trigonometric identify to simplify:
Then use the identify to simplify further:
Example Question #8 : Prove Trigonometric Identities
Simplify
To simplify the expression, separate the fraction into two parts:
The terms in the first fraction cancel leaving you with:
Then you can deal with the remaining fraction using the rule that . This leaves:
You can separate this into:
And each half of this expression is now a trigonometric identity: and . This gives you:
Example Question #1 : Evaluating Trig Functions
Find the value of to the nearest tenth if and .
Rewrite in terms of sine and cosine.
Substitute the known values and evaluate.
The answer to the nearest tenth is .
Example Question #1 : Find The Decimal Value Of A Trigonometric Function
Determine the value of in decimal form.
Ensure the calculator is in radian mode since the expression shows the angle in terms of . Also convert cotangent to tangent.
Example Question #1 : Evaluating Trig Functions
Find the decimal value of
To determine the decimal value of the following trig function, , make sure that the calculator is in radian mode.
Compute the expression.
Example Question #2 : Find The Decimal Value Of A Trigonometric Function
Determine the correct value of
.
The question asks for the y-coordinate on the unit circle when the degree angle is .
Be careful not to confuse finding the value of the angle when the y-value of the coordinate of the unit circle is .
Ensure that the calculator is in degree mode.
Example Question #2 : Find The Decimal Value Of A Trigonometric Function
Find the value of
.
Before beginning this problem on a calculator, though this is not necessary since these are special angles, ensure that the mode of the calculator is in degrees.
Input the values of the expression and solve.
Example Question #1 : Evaluating Trig Functions
Solve for all x on the interval
,
,
,
,
,
Solve for all x on the interval
We can begin by recalling which two quadrants have a positive sine. Because sine corresponds to the y-value, we know that sine is positive in quadrants I and II.
Next, recall where we get .
always corresponds to our -increment angles. In this case, the angles we are looking for are and , because those are the two -increment angles in the first two quadrants.
Now, you might be saying, "what about ? That is an increment of 45."
While that is true, , not
So our answer is:
,