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AndCos (A+B)=4/5 and Sin (A+B) = 24/25find the value of tan 2A |
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Answer» Answer: The value of tan(2A) is \frac{3}{4}[/tex] Step-by-step explanation: Given sin(A+B)=\frac{24}{25}sin(A+B)= 25 24
cos(A-B)=\frac{4}{5}cos(A−B)= 5 4
we have to find tan2A If sin(A+B)=\frac{24}{25}sin(A+B)= 25 24
then PERPENDICULAR is 24 and HYPOTENUSE is 25 then By PYTHAGORAS Theorem third side can be calculated as 25^{2}=24^{2}+Base^225 2 =24 2 +Base 2
⇒ Base is 7 Hence, tan(A+B)=\frac{24}{7}tan(A+B)= 7 24
Similarly, if cos(A-B)=\frac{4}{5}cos(A−B)= 5 4
then base is 4 and hypotenuse is 5 then By Pythagoras Theorem third side can be calculated as 5^{2}=4^{2}+Perpendicular^25 2 =4 2 +Perpendicular 2
⇒ Perpendicular is 3 Hence, tan(A-B)=\frac{3}{4}tan(A−B)= 4 3
∵ B>A, then A-B is negative.hence, taken negative tan(A-B)=\frac{-3}{4}tan(A−B)= 4 −3
tan(2A)=tan((A+B)+(A-B))= \frac{tan(A+B)+tan(A-B)}{1-tan(A+B)\times tan(A-B)}tan(2A)=tan((A+B)+(A−B))= 1−tan(A+B)×tan(A−B) tan(A+B)+tan(A−B)
⇒ tan(2A)=\frac{\frac{24}{7}+(\frac{-3}{4})}{1-\frac{24}{7}\times (\frac{-3}{4})}tan(2A)= 1− 7 24
×( 4 −3
) 7 24
+( 4 −3
)
=\frac{\frac{75}{28}}{\frac{100}{28}}=\frac{3}{4} 28 100
28 75
= 4 3
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