All Precalculus Resources
Example Questions
Example Question #1 : Trigonometric Operations
What is if and ?
In order to find we need to utilize the given information in the problem. We are given the opposite and adjacent sides. We can then, by definition, find the of and its measure in degrees by utilizing the function.
Now to find the measure of the angle using the function.
If you calculated the angle's measure to be then your calculator was set to radians and needs to be set on degrees.
Example Question #61 : Pre Calculus
If equals and is , how long is ?
Not enough information to solve
This problem can be easily solved using trig identities. We are given the hypotenuse and . We can then calculate side using the .
Rearrange to solve for .
If you calculated the side to equal then you utilized the function rather than the .
Example Question #2 : Graphing The Sine And Cosine Functions
What is the length of CB?
Example Question #11 : Triangles
In this figure, angle . If side and , what is the value of angle ?
Undefined
For this problem, use the law of sines:
.
In this case, we have values that we can plug in:
Example Question #62 : Pre Calculus
In this figure, if angle , side , and side , what is the value of angle ?
(NOTE: Figure not necessarily drawn to scale.)
Undefined
First, observe that this figure is clearly not drawn to scale. Now, we can solve using the law of sines:
.
In this case, we have values that we can plug in:
Example Question #1 : Applying Trigonometric Functions
In this figure, if angle , side , and side , what is the measure of angle ?
Undefined
Since , we know we are working with a right triangle.
That means that .
In this problem, that would be:
Plug in our given values:
Example Question #3 : Triangles
In this figure, , , and . What is the value of angle ?
Undefined
Notice that these sides fit the pattern of a 30:60:90 right triangle: .
In this case, .
Since angle is opposite , it must be .
Example Question #1 : Understanding 30 60 90 Triangles
A triangle has angles of . If the side opposite the angle is , what is the length of the side opposite ?
The pattern for is that the sides will be .
If the side opposite is , then the side opposite will be .
Example Question #5 : Triangles
A triangle has sides of length 12, 17, and 22. Of the measures of the three interior angles, which is the greatest of the three?
We can apply the Law of Cosines to find the measure of this angle, which we will call :
The widest angle will be opposite the side of length 22, so we will set:
, ,
Example Question #6 : Triangles
In , , , and . To the nearest tenth, what is ?
A triangle with these characteristics cannot exist.
By the Law of Cosines:
or, equivalently,
Substitute: