Cosine
Definition of Cosine

• In a right-angles Triangle Cosine is the Ratio of Length of the adjacent side to the Length of the hypotenuse.

More about Cosine

• Cosine is also written as cos.

Example of Cosine

• cos θ = & cos θ =

Solved Example on Cosine

If x = 8 units, y = 15 units, and a = 17 units, then find the Value of cos C in the Right Triangle ABC.

Choices:
A.
B.
C.
D.
Correct Answer: D
Solution:
Step 1: Cos C =
Step 2: In ΔABC, the adjacent side of C is and the Hypotenuse is .
Step 3: So, Cos C =
Step 4: = [Substitute BC = 8 and AC = 17.]

Related Terms for Cosine

• Adjacent Side
• Hypotenuse
• Length
• Right Triangle
• Sine
• Tan, Tangent
• Trigonometric Functions

Additional Links for Cosine

• Click here for samples
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