Advertisements
Advertisements
प्रश्न
Evaluate the following
cos2 30° + cos2 45° + cos2 60° + cos2 90°
Advertisements
उत्तर
cos2 30° + cos2 45° + cos2 60° + cos2 90° ....(i)
By trigonometric ratios we have
`cos 30^@ = sqrt3/2 cos 45^@ = 1/sqrt2`
`cos 60^@ = 1/2 cos 90^@ = 0`
By substituting above values in (i), we get
`[sqrt3/2]^2 + [1/sqrt2]^2 + [1/2]^2 + [1]^2`
`3/4 +1/2 + 1/4 = 0 => 1 + 1/2 = 3/2`
APPEARS IN
संबंधित प्रश्न
In Given Figure, find tan P – cot R.
In the following, trigonometric ratios are given. Find the values of the other trigonometric ratios.
`sec theta = 13/5`
If 3 tan θ = 4, find the value of `(4cos theta - sin theta)/(2cos theta + sin theta)`
If `cot theta = 1/sqrt3` show that `(1 - cos^2 theta)/(2 - sin^2 theta) = 3/5`
If `tan theta = 24/7`, find that sin θ + cos θ.
If `sin theta = a/b` find sec θ + tan θ in terms of a and b.
Evaluate the following
cos 60° cos 45° - sin 60° ∙ sin 45°
Evaluate the Following
4(sin4 60° + cos4 30°) − 3(tan2 60° − tan2 45°) + 5 cos2 45°
Find the value of x in the following :
`2sin 3x = sqrt3`
Find the value of x in the following :
cos 2x = cos 60° cos 30° + sin 60° sin 30°
If cosec θ - cot θ = `1/3`, the value of (cosec θ + cot θ) is ______.
The value of cos 0°. cos 1°. cos 2°. cos 3°… cos 89° cos 90° is ______.
If sin A = `1/2`, then the value of cot A is ______.
Find the value of sin 45° + cos 45° + tan 45°.
If sin θ + cos θ = `sqrt(2)` then tan θ + cot θ = ______.
Let f(x) = sinx.cos3x and g(x) = cosx.sin3x, then the value of `7((f(π/7) + g(π/7))/(g((5π)/14) + f((5π)/14)))` is ______.
The maximum value of the expression 5cosα + 12sinα – 8 is equal to ______.
If sinθ = `1/sqrt(2)` and `π/2 < θ < π`. Then the value of `(sinθ + cosθ)/tanθ` is ______.
If sin θ – cos θ = 0, then find the value of sin4 θ + cos4 θ.
Evaluate: 5 cosec2 45° – 3 sin2 90° + 5 cos 0°.
