Q. If sinA=2920 and cosB=5328 and angles A and B are in Quadrant I, find the value of tan(A−B).Answer:
Find Side Lengths: Use the sine and cosine values to find the lengths of the opposite and adjacent sides of the right triangles for angles A and B. For angle A, sinA=hypotenuseopposite=2920, which means the opposite side is 20 and the hypotenuse is 29. For angle B, cosB=hypotenuseadjacent=5328, which means the adjacent side is 28 and the hypotenuse is 53.
Calculate Missing Side: Calculate the missing side (adjacent for angle A and opposite for angle B) using the Pythagorean theorem.For angle A, adjacent side = hypotenuse2−opposite2=292−202=841−400=441=21.For angle B, opposite side = hypotenuse2−adjacent2=532−282=2809−784=2025=45.
Find Tangents: Now that we have the lengths of all sides of the right triangles for angles A and B, we can find tanA and tanB.tanA=adjacentopposite for angle A=2120.tanB=adjacentopposite for angle B=2845.
Use Angle Difference Identity: Use the angle difference identity for tangent to find tan(A−B):tan(A−B)=1+tanA⋅tanBtanA−tanB.Substitute the values of tanA and tanB into the formula:tan(A−B)=1+(2120⋅2845)2120−2845.
Simplify Expression: Simplify the expression for tan(A−B):tan(A−B)=((21×28)(20×28−45×21))/(1+(21×28)(20×45)).tan(A−B)=((588)(560−945))/(1+(588)(900)).tan(A−B)=((588)(−385))/(1+588900).
Find Common Denominator: Further simplify the expression by finding a common denominator for the terms in the denominator of the fraction:tan(A−B)=588−385/588588+900.tan(A−B)=588−385/5881488.
Simplify Complex Fraction: Simplify the complex fraction by multiplying the numerator by the reciprocal of the denominator: tan(A−B)=(−588385)×(1488588).
Cancel Common Factors: Cancel out the common factors in the numerator and the denominator: tan(A−B)=1488−385.
Reduce Fraction: Reduce the fraction to its simplest form: tan(A−B)=212−55.
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