Advertisements
Advertisements
प्रश्न
Express the following as a sum or difference
cos 5θ cos 2θ
Advertisements
उत्तर
cos 5θ cos 2θ
We know
cosA cosB = `1/2`[cos(A + B) + cos(A – B)]
Take A = 5θ, B = 2θ
cos 5θ . cos 2θ = `1/2`[cos(5θ + 2θ) + cos(5θ – 2θ)]
cos 5θ . cos 2θ = `1/2`[cos 7θ + cos 3θ]
APPEARS IN
संबंधित प्रश्न
Find the values of tan(1050°)
Find the values of `sin (-(11pi)/3)`
`(5/7, (2sqrt(6))/7)` is a point on the terminal side of an angle θ in standard position. Determine the six trigonometric function values of angle θ
Find all the angles between 0° and 360° which satisfy the equation sin2θ = `3/4`
Find the value of cos 105°.
Prove that cos(30° + x) = `(sqrt(3) cos x - sin x)/2`
Show that tan 75° + cot 75° = 4
If θ + Φ = α and tan θ = k tan Φ, then prove that sin(θ – Φ) = `("k" - 1)/("k" + 1)` sin α
If θ is an acute angle, then find `cos (pi/4 + theta/2)`, when sin θ = `8/9`
If cos θ = `1/2 ("a" + 1/"a")`, show that cos 3θ = `1/2 ("a"^3 + 1/"a"^3)`
Show that `cot(7 1^circ/2) = sqrt(2) + sqrt(3) + sqrt(4) + sqrt(6)`
Express the following as a product
sin 75° sin 35°
Show that `cos pi/15 cos (2pi)/15 cos (3pi)/15 cos (4pi)/15 cos (5pi)/15 cos (6pi)/15 cos (7pi)/15 = 1/128`
Prove that `(sin(4"A" - 2"B") + sin(4"B" - 2"A"))/(cos(4"A" - 2"B") + cos(4"B" - 2"A"))` = tan(A + B)
If A + B + C = 180°, prove that cos A + cos B − cos C = `- 1 + 4cos "A"/2 cos "B"/2 sin "C"/2`
If A + B + C = 180°, prove that sin(B + C − A) + sin(C + A − B) + sin(A + B − C) = 4 sin A sin B sin C
Choose the correct alternative:
`1/(cos 80^circ) - sqrt(3)/(sin 80^circ)` =
Choose the correct alternative:
If cos 28° + sin 28° = k3, then cos 17° is equal to
Choose the correct alternative:
Let fk(x) = `1/"k" [sin^"k" x + cos^"k" x]` where x ∈ R and k ≥ 1. Then f4(x) − f6(x) =
