Q. If cosA=54 and tanB=6011 and angles A and B are in Quadrant I, find the value of tan(A+B).Answer:
Find sinA: We know that cosA=54. To find tanA, we need to find sinA using the Pythagorean identity sin2A+cos2A=1.Substitute cosA=54 into the identity:(\sin A)^\(2 + \left(\frac{4}{5}\right)^2 = 1
Simplify equation: Simplify the equation to find (sinA)2:(sinA)2+2516=1(sinA)2=1−2516(sinA)2=2525−2516(sinA)2=259
Take square root: Take the square root of both sides to find sinA:sinA=±259Since angle A is in Quadrant I, where sine is positive, we choose the positive root:sinA=53
Find tanA: Now we can find tanA using sinA and cosA: tanA=cosAsinA tanA=4/53/5 tanA=43
Use angle sum identity: We are given tanB=6011. To find tan(A+B), we use the angle sum identity for tangent:tan(A+B)=1−tanA⋅tanBtanA+tanBSubstitute tanA=43 and tanB=6011 into the identity:tan(A+B)=1−(43)⋅(6011)43+6011
Find common denominator: Find a common denominator and simplify the numerator and denominator:tan(A+B)=1−33/24045/60+11/60tan(A+B)=1−33/24056/60tan(A+B)=(240/240)−(33/240)56/60tan(A+B)=207/24056/60
Simplify fractions: Simplify the fractions and perform the division:tan(A+B)=1514/240207tan(A+B)=1514×207240tan(A+B)=15×20714×240
Perform division: Simplify the multiplication and division: tan(A+B)=31053360 Now we simplify the fraction by dividing both the numerator and the denominator by their greatest common divisor, which is 15: tan(A+B)=207224
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