Trig identities

Question 1

Csc(x)=?

Answer 1

1/sin(x)

Question 2

Sec(x)=?

Answer 2

1/cos(x)

Question 3

Cot(x) = ?

Answer 3

1/tan(x)

Question 4

Tan(x)=?

Answer 4

Sin(x)/cos(x)

Question 5

Cot(x)=?

Answer 5

Cos(x) / sin(x)

Question 6

What are the Pythagorean identities?

Answer 6

Sin^2(x) + cos^2(x) = 1

Tan^(x) + 1 = sec^2(x)

1 + cot^2(x) = csc^2(x)

Question 7

What are the compound angle identities for sin?

Answer 7

Sin(a+b) = sin(a)cos(b) + sin(b)cos(a)

Sin(a - b) = sin(a)cos(b) - sin(b)cos(a)

Question 8

What are the compound angle identities for cos?

Answer 8

Cos(a+b) = cos(a)cos(b) - sin(a)sin(b)

Cos(a - b) = cos(a)cos(b) + sin(a)sin(b)

Question 9

What are the compound angle identities for tan?

Answer 9

Tan(a+b) = (tan(a) + tan(b)) / (1 - tan(a)tan(b))

Tan(a - b) = (tan(a) - tan(b)) / (1 + tan(a)tan(b))

Question 10

What are the Double angle identities?

Answer 10

Sin2(x) = 2(sin(x)cos(x))

Cos2(x) = cos^2(x) - sin^2(x)

Cos2(x) = 2cos^2(x) - 1

Cos2(x) = 1 - 2sin^2(x)

Tan2(x) = (2tan(x)) / (1 - tan^2(x))