Identifying Identities
1/sin(x) = csc(x) is an example of this type of identity.
What is a reciprocal identity.
Is this the Krusty Krab?
All solutions of 1 + 2cos x = 0.
What is (120° + n360°) degrees and (240° + n360°) degrees?
Sin(105°)
What is (√6 + √2)/4 ?
Using the ratio identity, tan(x) is equal to this ratio.
What is sin(x)/cos(x)?
Simplify:
(cos2 x)/(1 - sinx)
What is 1 + sin x?
The exact solutions of cos2 x - cos x - 2 = 0 for 0 < x < 360.
What is x = 180° ?
cos(15°)
What is (√6 + √2)/4 ?
sin2(x) + cos2(x) = 1 is an example of this kind of identity.
What is a Pythagorean Identity?
The cosine of an angle is equal to √2/2 at these two angles.
What is Pi/4 and 7Pi/4? (45 and 315 degrees).
The expression (cos x)(sin x)/(tan x) written in terms of a single trigonometric expression.
What is cos2 x?
The solution for 1 - sin2 x = cos2 x
What is all real numbers?
Cos(95°)Cos(55°)-Sin(95°)Sin(55°)
What is -√3/2 ?
sin(x + y) = sin(x)cos(y) + cos(x)sin(y) is this type of identity.
What is a sum and difference identity?
Verify the Trig Identity:
(sinx + cosx)2 + (sinx - cosx)2 = 2
(sinx + cosx)2 + (sinx - cosx)2
sin2x + 2cosxsinx + cos2x + sin2x - 2cosxsinx + cos2x
2sin2x + 2cos2x
2(sin2x + cos2x)
2(1)
2
1 + tan2 x + sec x = 0 solved for 0 < x < 360 degrees.
What is x = 180° ?
tan(255°)
What is 2 + √3 ?
sin (2x) = 2sinxcosx is an example of this type of identity.
What is a double angle identity?
On the unit circle, you can find tangent this way.
What is divide y by x?
(1 - tan2x)/(1 + tan2x) = 1-2sin2x
(1 - tan2x)/(1 + tan2x) =
(1 - tan2x)/(sec2x) =
(1 / sec2x) - (tan2x/sec2x) =
cos2x - sin2x =
(1 - sin2x) - sin2x =
1 - 2sin2x
The exact solutions for cos2 x + 2cos x = -2 when 0 < x < 360 degrees.
What is no solution?
cos 𝛼 = 8/17 and tan 𝛽 = 5/12 , the cos (𝛼 + 𝛽) is equal to...
What is 21/221 ?