Question
upstudy study bank question image url

Calculate without a calculator \( \frac{5}{\tan ^{2} A} \)\( \frac{\frac{7}{\cos ^{2} B}}{} \)

Ask by Warren Wade. in South Africa
Mar 09,2025

Upstudy AI Solution

Tutor-Verified Answer

Answer

The expression simplifies to \( 35 \cot^2 A \sec^2 B \).

Solution

We start with the expression \[ \frac{5}{\tan^2 A} \cdot \frac{7}{\cos^2 B}. \] **Step 1. Multiply the fractions.** Multiplying the numerators and denominators gives \[ \frac{5 \cdot 7}{\tan^2 A \cdot \cos^2 B} = \frac{35}{\tan^2 A \cos^2 B}. \] **Step 2. Express \(\tan^2 A\) in terms of sine and cosine.** Recall that \[ \tan A = \frac{\sin A}{\cos A} \quad \Rightarrow \quad \tan^2 A = \frac{\sin^2 A}{\cos^2 A}. \] Then, substitute into the expression: \[ \frac{35}{\frac{\sin^2 A}{\cos^2 A}\cos^2 B}. \] **Step 3. Simplify by multiplying by the reciprocal.** Multiply numerator and denominator by \(\cos^2 A\): \[ \frac{35 \cos^2 A}{\sin^2 A\, \cos^2 B}. \] **Step 4. Rewrite in alternative forms.** We can recognize that \[ \frac{\cos^2 A}{\sin^2 A} = \cot^2 A \quad \text{and} \quad \frac{1}{\cos^2 B} = \sec^2 B. \] Thus, the expression becomes \[ 35 \cot^2 A\, \sec^2 B. \] **Final Answer:** \[ 35 \cot^2 A\, \sec^2 B. \]

Answered by UpStudy AI and reviewed by a Professional Tutor

error msg
Explain
Simplify this solution

Beyond the Answer

To simplify \( \frac{5}{\tan^2 A} \cdot \frac{7}{\cos^2 B} \), start by recalling that \( \tan A = \frac{\sin A}{\cos A} \). Thus, \( \tan^2 A = \frac{\sin^2 A}{\cos^2 A} \), which gives us: \[ \frac{5}{\tan^2 A} = \frac{5 \cos^2 A}{\sin^2 A} \] Now, substituting this back into the expression, we have: \[ \frac{5 \cos^2 A}{\sin^2 A} \cdot \frac{7}{\cos^2 B} = \frac{35 \cos^2 A}{\sin^2 A \cdot \cos^2 B} \] This is the simplified form of the expression without a calculator. To find a numerical value, specific angles for \( A \) and \( B \) would be needed. For example, if \( A = 45^\circ \) and \( B = 60^\circ \), you’d find \( \tan^2 45^\circ = 1\), \( \sin^2 45^\circ = \frac{1}{2} \), and \( \cos^2 60^\circ = \frac{1}{4} \), allowing you to calculate the value.

Latest Trigonometry Questions

Try Premium now!
Try Premium and ask Thoth AI unlimited math questions now!
Maybe later Go Premium
Study can be a real struggle
Why not UpStudy it?
Select your plan below
Premium

You can enjoy

Start now
  • Step-by-step explanations
  • 24/7 expert live tutors
  • Unlimited number of questions
  • No interruptions
  • Full access to Answer and Solution
  • Full Access to PDF Chat, UpStudy Chat, Browsing Chat
Basic

Totally free but limited

  • Limited Solution
Welcome to UpStudy!
Please sign in to continue the Thoth AI Chat journey
Continue with Email
Or continue with
By clicking “Sign in”, you agree to our Terms of Use & Privacy Policy