Suppose sin (B) =.75. Calculate cos (A)

Question

Mathematics

Lexi Herring

6 December, 16:46

Suppose sin (B) =.75. Calculate cos (A)

+2

Answers (2)

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Maddison · Answer 1

SinB = 0.75

Recall: Sin²B + Cos²B = 1

0.75² + Cos²B = 1

0.5625 + Cos²B = 1

Cos²B = 1 - 0.5625

Cos²B = 0.4375

CosB = + or - √0.4375

Cos B ≈ + or - 0.6614

Estrella Lindsey · Answer 2

We use the formula (sinB) ^2 + (cosB) ^2 = 1;

But, sinB = 3/4;

Then, (cosB) ^2 = 1 - 9/16;

(cosB) ^2 = 7/16;

cosB = + or - √7 / 4;