Skip to main content
Ch. 3 - Trigonometric Identities and Equations
Blitzer - Trigonometry 3rd Edition
Blitzer3rd EditionTrigonometryISBN: 9780137316601Not the one you use?Change textbook
Chapter 3, Problem 67

In Exercises 67–74, rewrite each expression in terms of the given function or functions. tanx+cotxcscx\(\frac{\tan x+\cot x}{\csc x}\); cosx\(\cos\) x

Verified step by step guidance
1
Start by rewriting the given expression clearly: \( \frac{\tan x + \cot x}{\cos x \cdot \csc x} \).
Recall the definitions of the trigonometric functions involved: \( \tan x = \frac{\sin x}{\cos x} \), \( \cot x = \frac{\cos x}{\sin x} \), and \( \csc x = \frac{1}{\sin x} \).
Rewrite the numerator \( \tan x + \cot x \) as \( \frac{\sin x}{\cos x} + \frac{\cos x}{\sin x} \). Find a common denominator to combine these two terms.
Rewrite the denominator \( \cos x \cdot \csc x \) as \( \cos x \cdot \frac{1}{\sin x} = \frac{\cos x}{\sin x} \).
Now, express the entire fraction as \( \frac{\frac{\sin x}{\cos x} + \frac{\cos x}{\sin x}}{\frac{\cos x}{\sin x}} \). Simplify this complex fraction by multiplying numerator and denominator appropriately to eliminate the complex fraction.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Reciprocal Trigonometric Functions

Reciprocal functions relate pairs like sine and cosecant, cosine and secant, tangent and cotangent. For example, csc x = 1/sin x and cot x = 1/tan x. Understanding these relationships helps rewrite expressions by substituting one function with its reciprocal.
Recommended video:
6:04
Introduction to Trigonometric Functions

Simplifying Complex Fractions

Complex fractions involve a fraction divided by another fraction or expression. Simplifying requires rewriting the numerator and denominator in terms of common functions, then multiplying by the reciprocal of the denominator to simplify the overall expression.
Recommended video:
4:22
Dividing Complex Numbers

Expressing Trigonometric Expressions in Terms of a Given Function

This involves rewriting all parts of an expression using only the specified trigonometric function(s). For example, expressing tan x and cot x in terms of sin x and cos x, or rewriting everything in terms of cos x and csc x, to meet the problem's requirements.
Recommended video:
6:36
Simplifying Trig Expressions