The Trigonometric function sin(A - B) = (3 - 2[tex]\sqrt{14}[/tex]) ÷ 12
What is trigonometry?
- The study of correlations between triangles side lengths and angles is known as trigonometry.
- In geometric figures, unknown angles and distances are derived from known or measured angles using trigonometric functions.
- The need to calculate angles and distances in disciplines like astronomy, mapmaking, surveying, and artillery range finding led to the development of trigonometry.
The easiest way is to use the Pythagorean Identity to find both cos A and sin B. Then use the sum/difference angle identity for sine.
The trigonometric Pythagorean identity tells us that,
[tex]Sin^{2}[/tex]θ + [tex]cos^{2}[/tex]θ = 1
which follows directly from the geometric identity for right triangles and the fact that,
sinθ = y/r and cosθ = x/r
If r is the distance (x,y) is from the origin, then
[tex]x^{2}[/tex] + [tex]y^{2}[/tex] = [tex]r^{2}[/tex]
[tex](x/r)^{2}[/tex] + [tex](y/r)^{2}[/tex] = 1(divide both sides by [tex]r^{2}[/tex])
[tex]cos^{2}[/tex]θ + [tex]Sin^{2}[/tex]θ = 1
Anyway, if we know sin A (and which quadrant it ends in), we can solve for cos A and vice versa:
[tex]Sin^{2}[/tex]θ + [tex]cos^{2}[/tex]θ = 1
[tex](1/3)^{2}[/tex] + [tex]cos^{2}[/tex]θ = 1
⇒ cos A = [tex]\sqrt{1-(1/3)^{2} }[/tex] = [tex]\frac{2\sqrt{2}}{3}[/tex]
cosθ is always negative in this quadrant.
Therefore,
cos A = -[tex]\frac{2\sqrt{2} }{3}[/tex]
Similar reasoning can be done with cos B = [tex]\frac{3}{4}[/tex] to show that sin B = -[tex]\frac{\sqrt{7} }{4}[/tex]
Now that we have all the necessary elements, we can use the sum/difference angle identity:
Sin(A-B) = sin A cos B - cos A sin B
= ( [tex]\frac{1}{3}[/tex] × [tex]\frac{3}{4}[/tex] ) - ( (-[tex]\frac{2\sqrt{2} }{3}[/tex] ) × (-[tex]\sqrt{7[/tex]/4) )
= (3 ÷ 12) - (2[tex]\sqrt{14}[/tex] ÷ 12)
= (3 - 2[tex]\sqrt{14}[/tex]) ÷ 12
We get sin(A - B) = (3 - 2[tex]\sqrt{14}[/tex]) ÷ 12
To learn more about trigonometry refer to;
https://brainly.com/question/20519838
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