Conditional Identities

IMPORTANT

Conditional Identities: Overview

This topic covers concepts, such as, Trigonometric Identities and Inequalities Based on Triangles, Conditional Identities Based on Triangles & Trigonometric Inequalities Based on Triangle etc.

Important Questions on Conditional Identities

MEDIUM
IMPORTANT

If the line x=y=z intersects the line x sinA+y sinB+z sinC-18=0=x sin2A+y sin2B+zsin2C-9, where A, B, C are the angles of a triangle ABC, then 80sinA2sinB2sinC2 is equal to _________.

EASY
IMPORTANT

The value of sin148°+sin56°+sin156°cos74°+cos28°+cos78°-1cos37°cos14°cos39° is

MEDIUM
IMPORTANT

If sin-1a+sin-1b+sin-1c=π , then the value of a 1-a2+b1-b2+c1-c2 will be

MEDIUM
IMPORTANT

In a triangle ABC, cotA + cotB + cotC = cotθ .

sinAsinBsinC1+cosAcosBcosC=

HARD
IMPORTANT

In a triangle ABC, if cotA + cotB + cotC = cotθ, then the possible value of θ  is-

HARD
IMPORTANT

If x+y+z=xyz , then the value of x1-y2 1-z2+y1-x21-z2+z1-x21-y2 is

HARD
IMPORTANT

Statement - 1: The minimum value of the expression sinα+sinβ+sinγ where α, β, γ are real numbers such that α+β+γ=π , is not – 3 

Statement - 2: α, β, γ are angles of a triangle

HARD
IMPORTANT

  Column – I   Column – II
A. In an acute angled triangle ABC, the least values of secA and tan2A are λ and μ respectively, then p. λ+μ=2
B. In a triangle ABC, the least values of cosecA2 and sec2A2 are λ and μ respectively, then q. μ-λ=3
C. In a triangle ABC, the least values of cosecA2 and cosec2A are λ and μ respectively, then r. λ-μ=4
    s. 3λ-2μ=0
    t. 2λ-3μ=2

HARD
IMPORTANT

In a ΔABC, if cosAcosBcosC=3-18 and sinA.sinB.sinC=3+ 38 , then on the basis of above information, answer the following questions:

The value of tanA+tanB+tanC is:

EASY
IMPORTANT

In a triangle ABC, if a = 7, b = 8, c = 9, then the length of the line joining B to the midpoint of AC is

MEDIUM
IMPORTANT

If tanA:tanB:tanC=1:2:3A+B+C=π, then sinA:sinB:sinC is equal to

EASY
IMPORTANT

If in ΔABCtanA+tanB+tanC=x2+6x+5, then set of values of x for which ΔABC is obtuse angled,

HARD
IMPORTANT

If A+B+C=π and cosAcosecBcosecC=k, then k is equal to

MEDIUM
IMPORTANT

If in a ABC, C=90°, then the maximum value of sinAsinB is

HARD
IMPORTANT

In a ABC,cosB+2C+3A2+cosA-B2 is equal to

MEDIUM
IMPORTANT

If A+B+C=π, then cos2A+cos2B+cos2C+2cosAcosBcosC is equal to

MEDIUM
IMPORTANT

Find value of ΣcosA.cosecB.cosecC ,for any triangle ABC which is not right angled.

HARD
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There exist a ABC satisfying

HARD
IMPORTANT

If the line x=y=z intersects the line sinA·x+sinB·y+sinC·z=2d2, sin2A·x+sin2B·y+sin2C·z=d2 then sinA2sinB2sinC2 is equal to (where A+B+C=π)