Trigonometic Identities

trig identities for AP Precal :)

sin(x) can be rewritten as…

1/csc(x)

cos(x) can be rewritten as…

1/sec(x)

tan(x) can be rewritten as…(two answers)

sin(x)/cos(x) OR 1/cot(x)

csc(x) can be rewritten as…

1/sin(x)

sec(x) can be rewritten as…

1/cos(x)

cot(x) can be rewritten as…(two answers)

cos(x)/sin(x) OR 1/tan(x)

The basic pythagorean identity is…

sin²(x) + cos²(x) = 1

sin²(x) can be rewritten as…

1 - cos²(x)

cos²(x) can be rewritten as…

1 - sin²(x)

sec²(x) can be rewritten as…

tan²(x) + 1

tan²(x) can be rewritten as…

sec²(x) - 1

csc²(x) can be rewritten as…

cot²(x) + 1

cot²(x) can be rewritten as…

csc²(x) - 1

cos(A+B) can be rewritten as…

cosAcosB - sinAsinB

cos(A-B) can be rewritten as…

cosAcosB + sinAsinB

sin(A+B) can be rewritten as…

sinAcosB + cosAsinB

sin(A-B) can be rewritten as…

sinAcosB - cosAsinB

for a cosine sum and difference identity, the sign…

changes

for a sine sum and difference identity, the sign

stays the same

sin(2x) can be rewritten as…

2sin(x)cos(x)

cos(2x) can be rewritten as…(3 answers)

cos²(x)-sin²(x), 1 - 2sin²(x), OR 2cos²(x) - 1