Trigonometric Identities |
(Math | Trig | Identities) |
sin(theta) = a / c | csc(theta) = 1 / sin(theta) = c / a |
cos(theta) = b / c | sec(theta) = 1 / cos(theta) = c / b |
tan(theta) = sin(theta) / cos(theta) = a / b | cot(theta) = 1/ tan(theta) = b / a |
sin^2(x) + cos^2(x) = 1 | tan^2(x) + 1 = sec^2(x) | cot^2(x) + 1 = csc^2(x) |
sin(x y) = sin x cos y cos x sin y | ||
cos(x y) = cos x cosy sin x sin y |
angle | 0 | 30 | 45 | 60 | 90 |
---|---|---|---|---|---|
sin^2(a) | 0/4 | 1/4 | 2/4 | 3/4 | 4/4 |
cos^2(a) | 4/4 | 3/4 | 2/4 | 1/4 | 0/4 |
tan^2(a) | 0/4 | 1/3 | 2/2 | 3/1 | 4/0 |
| (Law of Cosines) |
a2 + b2 = c2
In a right angled triangle:
the square of the hypotenuse is equal to
the sum of the squares of the other two sides. Free five line slots.
Let's check if the areas are the same: Securityspy 4 2 3 – multi camera video surveillance app. 32 + 42 = 52 Calculating this becomes: 9 + 16 = 25 It works . like Magic! |
Yes, it does have a Right Angle!
Yes, it does!
becomes |
Historical Note: while we call it Pythagoras' Theorem, it was also known by Indian, Greek, Chinese and Babylonian mathematicians well before he lived ! |