Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

If 
cos A=(9)/(41) and 
tan B=(5)/(12) and angles A and B are in Quadrant I, find the value of 
tan(A-B).
Answer:

If cosA=941 \cos A=\frac{9}{41} and tanB=512 \tan B=\frac{5}{12} and angles A and B are in Quadrant I, find the value of tan(AB) \tan (A-B) .\newlineAnswer:

Full solution

Q. If cosA=941 \cos A=\frac{9}{41} and tanB=512 \tan B=\frac{5}{12} and angles A and B are in Quadrant I, find the value of tan(AB) \tan (A-B) .\newlineAnswer:
  1. Use tan(AB)\tan(A-B) Identity: Use the identity for tan(AB)\tan(A-B), which is tan(AB)=tanAtanB1+tanAtanB\tan(A-B) = \frac{\tan A - \tan B}{1 + \tan A \cdot \tan B}. We need to find tanA\tan A and tanB\tan B to use this formula.
  2. Find sinA\sin A: We know that cosA=941\cos A = \frac{9}{41} and tanB=512\tan B = \frac{5}{12}. Since AA is in Quadrant I, sinA\sin A will be positive. Use the Pythagorean identity sin2A+cos2A=1\sin^2 A + \cos^2 A = 1 to find sinA\sin A.sin2A=1cos2A\sin^2 A = 1 - \cos^2 Asin2A=1(941)2\sin^2 A = 1 - \left(\frac{9}{41}\right)^2sin2A=1811681\sin^2 A = 1 - \frac{81}{1681}cosA=941\cos A = \frac{9}{41}00cosA=941\cos A = \frac{9}{41}11cosA=941\cos A = \frac{9}{41}22cosA=941\cos A = \frac{9}{41}33
  3. Find tanA\tan A: Now, find tanA\tan A using the definition tanA=sinAcosA\tan A = \frac{\sin A}{\cos A}.tanA=(40/41)(9/41)\tan A = \frac{(40/41)}{(9/41)}tanA=409\tan A = \frac{40}{9}
  4. Substitute tanA\tan A and tanB\tan B: Substitute the values of tanA\tan A and tanB\tan B into the identity for tan(AB)\tan(A-B).\newlinetan(AB)=tanAtanB1+tanAtanB\tan(A-B) = \frac{\tan A - \tan B}{1 + \tan A \cdot \tan B}\newlinetan(AB)=4095121+(409)(512)\tan(A-B) = \frac{\frac{40}{9} - \frac{5}{12}}{1 + \left(\frac{40}{9}\right) \cdot \left(\frac{5}{12}\right)}
  5. Simplify with Common Denominator: Simplify the expression by finding a common denominator for tanA\tan A and tanB\tan B.tan(AB)=(409×1212512×99)/(1+409×512)\tan(A-B) = \left(\frac{40}{9} \times \frac{12}{12} - \frac{5}{12} \times \frac{9}{9}\right) / \left(1 + \frac{40}{9} \times \frac{5}{12}\right)tan(AB)=(48010845108)/(1+200108)\tan(A-B) = \left(\frac{480}{108} - \frac{45}{108}\right) / \left(1 + \frac{200}{108}\right)tan(AB)=(435108)/(1+200108)\tan(A-B) = \left(\frac{435}{108}\right) / \left(1 + \frac{200}{108}\right)
  6. Simplify Denominator: Simplify the denominator of the expression. \newline1+200108=108108+2001081 + \frac{200}{108} = \frac{108}{108} + \frac{200}{108}\newline1+200108=3081081 + \frac{200}{108} = \frac{308}{108}
  7. Divide Numerator by Denominator: Now, divide the numerator by the denominator.\newlinetan(AB)=435108/308108\tan(A-B) = \frac{435}{108} / \frac{308}{108}\newlinetan(AB)=435108×108308\tan(A-B) = \frac{435}{108} \times \frac{108}{308}
  8. Simplify Expression: Simplify the expression by canceling out the common factor of 108108. \newlinetan(AB)=435308\tan(A-B) = \frac{435}{308}
  9. Check for Further Simplification: Check if the fraction can be simplified further. 435435 and 308308 have no common factors other than 11, so the fraction is already in its simplest form.

More problems from Find trigonometric ratios using multiple identities