Q. If tanA=724 and cosB=3712 and angles A and B are in Quadrant I, find the value of tan(A−B).Answer:
Use tan(A−B) formula: Use the formula for tan(A−B), which is tan(A−B)=1+tanA⋅tanBtanA−tanB. We know tanA=724, but we need to find tanB.
Find sinB: To find tanB, we need to use the Pythagorean identity sin2B+cos2B=1 to find sinB. We know cosB=3712, so we can calculate sinB. sin2B=1−cos2B=1−(3712)2.
Find common denominator: Now we have tanA and tanB, so we can use the tan(A−B) formula.tan(A−B)=1+tanA⋅tanBtanA−tanB=1+(724)⋅(1235)(724)−(1235).
Perform subtraction: Find a common denominator and subtract 724 and 1235. The common denominator is 7×12=84. tan(A−B)=1+(7×1224×35)(7×1224×12−12×735×7).
Simplify numerator and denominator: Perform the subtraction in the numerator. tan(A−B)=1+(840/84)(288−245)/84.
Divide numerator by denominator: Simplify the numerator and the term inside the parentheses in the denominator. tan(A−B)=8443/(1+10).
Simplify fraction: Simplify the denominator. tan(A−B)=8443/11.
Simplify fraction: Simplify the denominator. tan(A−B)=8443/11. Divide the numerator by the denominator. tan(A−B)=84×1143=92443.
Simplify fraction: Simplify the denominator. tan(A−B)=8443/11. Divide the numerator by the denominator. tan(A−B)=84×1143=92443. Simplify the fraction. tan(A−B)=92443 can be simplified by dividing both numerator and denominator by 4. tan(A−B)=92443=4×23143=92443=4×211=841.
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