Answer:
<h2>
cos 30°= 0.866</h2>
Step-by-step explanation:
Step one:
Applying the SOH CAH TOA principle
assuming all dimensions are in cm
Step two:
Given data
opposite= 1 cm
hypotenuse= 2 cm
<h3>we can now solve for θ</h3>
Sin(θ)= opp/hyp
Sin(θ)= 1/2
Sin(θ)= 0.5
θ= sin-1 0.5
θ= 30°
hence from tables cos 30°= 0.866
Recall some identities:
tan(x) = sin(x) / cos(x)
cos(x + y) = cos(x) cos(y) - sin(x) sin(y)
cos(x - y) = cos(x) cos(y) + sin(x) sin(y)
sin(x - y) = sin(x) cos(y) - cos(x) sin(y)
This means we have
• cos²(90° - x) = [cos(90°) cos(x) + sin(90°) sin(x)]²
… = sin²(x)
• tan(180° - x) = sin(180° - x) / cos(180° - x)
… = [sin(180°) cos(x) - cos(180°) sin(x)] / [cos(180°) cos(x) + sin(180°) sin(x)]
… = sin(x) / (-cos(x))
… = -tan(x)
(and we also get sin(180° - x) = sin(x))
• cos(180° + x) = cos(180°) cos(x) - sin(180°) sin(x)
… = -cos(x)
So, the given expression reduces to
sin²(x) (-tan(x)) (-cos(x)) / sin(x) = sin²(x)
since tan(x) and cos(x)/sin(x) = 1/tan(x) will cancel.
47: 2x * (3x^2 + x) = 6x^3 + 2x^2
48: (y^3 + 2) * 4y^2 = 4y^5 + 8y^2
It should be this answer i got it off the internet it should be right
