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In Mathematics / High School | 2025-07-03

If tan A = 3/4, then sin A cos A = 12/25.

Asked by troyawilliams3596

Answer (1)

To solve the problem, we are given that tan A = 4 3 ​ . We need to determine whether sin A cos A = 25 12 ​ is true.
Step-by-step:

Understanding Tangent : Given that tan A = 4 3 ​ , we know the relationship between the sides of a right triangle:


Opposite side: 3

Adjacent side: 4



Finding the Hypotenuse : We use the Pythagorean theorem to find the hypotenuse c :
c = 3 2 + 4 2 ​ = 9 + 16 ​ = 25 ​ = 5

Calculating Sine and Cosine :



sin A = Hypotenuse Opposite ​ = 5 3 ​

cos A = Hypotenuse Adjacent ​ = 5 4 ​



Compute sin A cos A :
sin A cos A = ( 5 3 ​ ) ( 5 4 ​ ) = 25 12 ​

Therefore, sin A cos A = 25 12 ​ is indeed true.

Answered by SophiaElizab | 2025-07-06