Trigonometry Flashcards
1 radian – in degrees
180 / π degrees
2 π radians – in degrees
360º
cos (A + B)
cos A cos B - sin A sin B
cos (A - B)
cos A cos B + sin A sin B
cos 2A – (sin form)
1 - 2sin² A
cos 2A – (cos form)
2cos² A - 1
cos 2A – (both)
cos² A - sin² A
cos 30º
sqrt(3) / 2
sqrt is an abbreviation for “square root”
cos 45º
1 / sqrt(2)
sqrt is an abbreviation for “square root”
cos 60º
1/2
cos x
adjacent / hypotenuse
sin (A + B)
sin A cos B + cos A sin B
sin (A - B)
sin A cos B - cos A sin B
sin 2A
2 sin A cos A
sin 30º
1/2
sin 45º
1 / sqrt(2)
sqrt is an abbreviation for “square root”
sin 60º
sqrt(3) / 2
sqrt is an abbreviation for “square root”
sin x
opposite / hypotenuse
tan 30º
1 / sqrt(3)
sqrt is an abbreviation for “square root”
tan 45º
1
tan 60º
1 / sqrt(3)
sqrt is an abbreviation for “square root”
tan x
opposite / adjacent
xº – in radians
(π / 180) * x radians
* is often used to denote multiplication to avoid confusion with x
x radians – in degrees
(180 / π) * x degrees
* is often used to denote multiplication to avoid confusion with x
amplitude (trig)
The ampiltude of a trigonmetric function is half the distance between the minimum and maximum values.
(max - min)/2
period (trig)
For a repeating function like y = sin x, or y = cos x, the period is the horizontal length of one complete wave or cycle.
frequency (trig)
The number of cycles a trig function completes in a given interval, usually 360º or 2π radians for the sine or cosine functions.
phase angle
In y = sin (x + d), the constant d, controls the distance the graph of y = sin x is shifted along the x-axis.
If d is positive the shift is to the left. If d is negative the shift is to the right.
