Q. If sinA=4140 and cosB=2920 and angles A and B are in Quadrant I, find the value of tan(A−B).Answer:
Find cos(A): Use the Pythagorean identity to find cos(A). Since sin(A)=4140 and A is in Quadrant I, we can use the Pythagorean identity sin2(A)+cos2(A)=1 to find cos(A). cos2(A)=1−sin2(A)cos2(A)=1−(4140)2cos2(A)=1−16811600cos2(A)=16811681−16811600cos(A)0cos(A)1cos(A)2
Find sin(B): Use the Pythagorean identity to find sin(B).Since cos(B)=2920 and B is in Quadrant I, we can use the Pythagorean identity sin2(B)+cos2(B)=1 to find sin(B).sin2(B)=1−cos2(B)sin2(B)=1−(2920)2sin2(B)=1−841400sin2(B)=841841−841400sin(B)0sin(B)1sin(B)2
Find tan(A−B): Use the angle subtraction formula for tangent to find tan(A−B). The formula for tan(A−B) is 1+tan(A)tan(B)tan(A)−tan(B). We already have sin(A) and cos(A), and sin(B) and cos(B), so we can find tan(A) and tan(B). tan(A−B)0tan(A−B)1tan(A−B)2tan(A−B)3tan(A−B)4tan(A−B)5 Now we can find tan(A−B). tan(A−B)7tan(A−B)8
Find tan(A−B): Use the angle subtraction formula for tangent to find tan(A−B). The formula for tan(A−B) is 1+tan(A)tan(B)tan(A)−tan(B). We already have sin(A) and cos(A), and sin(B) and cos(B), so we can find tan(A) and tan(B). tan(A−B)0tan(A−B)1tan(A−B)2tan(A−B)3tan(A−B)4tan(A−B)5 Now we can find tan(A−B). tan(A−B)7tan(A−B)8Simplify the expression for tan(A−B). tan(A−B)8 To subtract the fractions, find a common denominator. Common denominator for tan(A−B)1 and tan(A−B)2 is tan(A−B)3. tan(A−B)4tan(A−B)5tan(A−B)6tan(A−B)7 Now simplify the expression. tan(A−B)8tan(A−B)9
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