Advertisements
Advertisements
प्रश्न
If `sqrt(3) tan θ` = 1, then find the value of sin2θ – cos2θ.
उत्तर
Given that,
`sqrt(3) tan θ` = 1
⇒ tan θ = `1/sqrt(3)` = tan 30°
⇒ θ = 30°
Now, sin2θ – cos2θ = sin230° – cos230°
= `(1/2)^2 - (sqrt(3)/2)^2`
= `1/4 - 3/4`
= `(1 - 3)/4`
= `-2/4`
= `-1/2`
APPEARS IN
संबंधित प्रश्न
Prove the following identities:
`(i) (sinθ + cosecθ)^2 + (cosθ + secθ)^2 = 7 + tan^2 θ + cot^2 θ`
`(ii) (sinθ + secθ)^2 + (cosθ + cosecθ)^2 = (1 + secθ cosecθ)^2`
`(iii) sec^4 θ– sec^2 θ = tan^4 θ + tan^2 θ`
If m=(acosθ + bsinθ) and n=(asinθ – bcosθ) prove that m2+n2=a2+b2
(secA + tanA) (1 − sinA) = ______.
if `a cos^3 theta + 3a cos theta sin^2 theta = m, a sin^3 theta + 3 a cos^2 theta sin theta = n`Prove that `(m + n)^(2/3) + (m - n)^(2/3)`
Prove the following identities:
`cot^2A/(cosecA + 1)^2 = (1 - sinA)/(1 + sinA)`
Prove the following identities:
`1 - cos^2A/(1 + sinA) = sinA`
Prove the following identities:
`(sinA + cosA)/(sinA - cosA) + (sinA - cosA)/(sinA + cosA) = 2/(2sin^2A - 1)`
Prove that:
2 sin2 A + cos4 A = 1 + sin4 A
`(cos^3 theta +sin^3 theta)/(cos theta + sin theta) + (cos ^3 theta - sin^3 theta)/(cos theta - sin theta) = 2`
Show that none of the following is an identity:
(i) `cos^2theta + cos theta =1`
Write the value of `( 1- sin ^2 theta ) sec^2 theta.`
The value of sin2 29° + sin2 61° is
Simplify
sin A `[[sinA -cosA],["cos A" " sinA"]] + cos A[[ cos A" sin A " ],[-sin A" cos A"]]`
Prove the following identity :
`(cosecA - sinA)(secA - cosA) = 1/(tanA + cotA)`
Prove the following identity :
`cosA/(1 - tanA) + sin^2A/(sinA - cosA) = cosA + sinA`
Prove the following identity :
`(1 + tan^2θ)sinθcosθ = tanθ`
Given `cos38^circ sec(90^circ - 2A) = 1` , Find the value of <A
Prove that: `sqrt((1 - cos θ)/(1 + cos θ)) = cosec θ - cot θ`.
tan2θ – sin2θ = tan2θ × sin2θ. For proof of this complete the activity given below.
Activity:
L.H.S = `square`
= `square (1 - (sin^2theta)/(tan^2theta))`
= `tan^2theta (1 - square/((sin^2theta)/(cos^2theta)))`
= `tan^2theta (1 - (sin^2theta)/1 xx (cos^2theta)/square)`
= `tan^2theta (1 - square)`
= `tan^2theta xx square` .....[1 – cos2θ = sin2θ]
= R.H.S
sec θ when expressed in term of cot θ, is equal to ______.