Advertisements
Advertisements
प्रश्न
State whether the following is true or false. Justify your answer.
sin (A + B) = sin A + sin B
पर्याय
True
False
उत्तर
This statement is False.
Explanation:
sin (A + B) = sin A + sin B
Let A = 30° and B = 60°
sin (A + B) = sin (30° + 60°)
= sin 90°
= 1
sin A + sin B = sin 30° + sin 60°
= `1/2 + (sqrt3)/2`
= `(1+sqrt3)/2`
Clearly, sin (A + B) ≠ sin A + sin B
Hence, the given statement is false.
APPEARS IN
संबंधित प्रश्न
Evaluate the following in the simplest form:
sin 60° cos 30° + cos 60° sin 30°
Evaluate the following:
`(5cos^2 60° + 4sec^2 30° - tan^2 45°)/(sin^2 30° + cos^2 30°)`
Express each one of the following in terms of trigonometric ratios of angles lying between
0° and 45°
Sin 59° + cos 56°
If A, B, C are the interior angles of a triangle ABC, prove that
`tan ((C+A)/2) = cot B/2`
Prove that `cos 80^@/sin 10^@ + cos 59^@ cosec 31^@ = 2`
Prove the following
sin (50° − θ) − cos (40° − θ) + tan 1° tan 10° tan 20° tan 70° tan 80° tan 89° = 1
Evaluate: `sin 50^@/cos 40^@ + (cosec 40^@)/sec 50^@ - 4 cos 50^@ cosec 40^@`
Evaluate: tan 7° tan 23° tan 60° tan 67° tan 83°
Evaluate: `cos 58^@/sin 32^@ + sin 22^@/cos 68^@ - (cos 38^@ cosec 52^@)/(tan 18^@ tan 35^@ tan 60^@ tan 72^@ tan 65^@)`
If A = 30°;
show that:
sin 3 A = 4 sin A sin (60° - A) sin (60° + A)
find the value of :
`( tan 45°)/ (cos ec30°) +( sec60°)/(co 45°) – (5 sin 90°)/ (2 cos 0°)`
Prove that:
`((tan60° + 1)/(tan 60° – 1))^2 = (1+ cos 30°) /(1– cos 30°) `
Prove that:
4 (sin4 30° + cos4 60°) -3 (cos2 45° - sin2 90°) = 2
If sec A = cosec A and 0° ∠A ∠90°, state the value of A
Given A = 60° and B = 30°,
prove that: tan (A - B) = `(tan"A" – tan"B")/(1 + tan"A".tan"B")`
If A =30o, then prove that :
cos 2A = cos2A - sin2A = `(1 – tan^2"A")/(1+ tan^2"A")`
Without using tables, evaluate the following: sin230° cos245° + 4tan230° + sin290° + cos20°
Without using tables, find the value of the following: `(4)/(cot^2 30°) + (1)/(sin^2 60°) - cos^2 45°`
If A = 30° and B = 60°, verify that: `(sin("A" -"B"))/(sin"A" . sin"B")` = cotB - cotA
If tan `"A" = (1)/(2), tan "B" = (1)/(3) and tan("A" + "B") = (tan"A" + tan"B")/(1 - tan"A" tan"B")`, find A + B.