Advertisements
Advertisements
Question
If A = 30°;
show that:
`(1 – cos 2"A")/(sin 2"A") = tan"A"`
Solution
Given that A = 30°
LHS = `(1 – cos2 "A")/(sin 2"A")`
= `(1 – cos 2 (30°))/(sin2 (30°))`
= `(1 – (1)/(2))/((sqrt3)/(2)`
= `(1)/(sqrt3)`
RHS = tan A
= tan 30°
= `(1)/(sqrt3)`
LHS = RHS
APPEARS IN
RELATED QUESTIONS
`(2 tan 30°)/(1-tan^2 30°)` = ______.
Evaluate the following
`sec 11^@/(cosec 79^@)`
Evaluate the following :
`(sec 70^@)/(cosec 20^@) + (sin 59^@)/(cos 31^@)`
Evaluate the following :
(sin 72° + cos 18°) (sin 72° − cos 18°)
Express each one of the following in terms of trigonometric ratios of angles lying between 0° and 45°
tan 65° + cot 49°
Express each one of the following in terms of trigonometric ratios of angles lying between 0° and 45°
sin 67° + cos 75°
If Sin 3A = cos (A – 26°), where 3A is an acute angle, find the value of A =?
Prove the following
`(tan (90 - A) cot A)/(cosec^2 A) - cos^2 A =0`
Evaluate: `sin 50^@/cos 40^@ + (cosec 40^@)/sec 50^@ - 4 cos 50^@ cosec 40^@`
Express each of the following in terms of trigonometric ratios of angles lying between 0° and 45°.
sin67° + cos75°
Express each of the following in terms of trigonometric ratios of angles lying between 0° and 45°.
sec78° + cosec56°
If cos 20 = sin 4 θ ,where 2 θ and 4 θ are acute angles, then find the value of θ
Find the value of:
tan2 30° + tan2 45° + tan2 60°
If sin x = cos x and x is acute, state the value of x
find the value of :
3sin2 30° + 2tan2 60° - 5cos2 45°
prove that:
tan (2 x 30°) = `(2 tan 30°)/(1– tan^2 30°)`
If A = 30°;
show that:
(sinA - cosA)2 = 1 - sin2A
If A = 30°;
show that:
4 cos A cos (60° - A). cos (60° + A) = cos 3A
Without using tables, evaluate the following: tan230° + tan260° + tan245°
Without using table, find the value of the following:
`(sin30° - sin90° + 2cos0°)/(tan30° tan60°)`
Without using tables, find the value of the following: `(sin30°)/(sin45°) + (tan45°)/(sec60°) - (sin60°)/(cot45°) - (cos30°)/(sin90°)`
Prove that : sec245° - tan245° = 1
Find the value of x in the following: `2sin x/(2)` = 1
Find the value of x in the following: `sqrt(3)sin x` = cos x
Find the value of the following:
`(tan45^circ)/("cosec"30^circ) + (sec60^circ)/(cot45^circ) - (5sin90^circ)/(2cos0^circ)`
Find the value of 8 sin 2x, cos 4x, sin 6x, when x = 15°
If sin 30° = x and cos 60° = y, then x2 + y2 is
Evaluate: `(5 "cosec"^2 30^circ - cos 90^circ)/(4 tan^2 60^circ)`
