trig identities
sin(-x) = ?
-sin(x)
cos(-x) = ?
cos(x)
tan(-x) = ?
tan(x)
sin^2(x) + cos^2(x) = ?
1
tan^2(x) + 1 = ?
sec^2(x)
1+cot^2(x) = ?
csc^2(x)
sin(pi/2 - x) = ?
cos(x)
cos(pi/2 - x) = ?
sin(x)
tan(pi/2 - x) = ?
cot(x)
cot(pi/2 - x) = ?
tan(x)
sin(a+b) = ?
sin(a)cos(b) + sin(b)cos(a)
sin(a - b) = ?
sin(a)cos(b) - sin(b)cos(a)
cos(a + b) = ?
cos(a)cos(b) - sin(a)sin(b)
cos(a - b) = ?
cos(a)cos(b) + sin(a)sin(b)
tan(a + b) = ?
{tan(a) + tan(b)} / {1 - tan(a)tan(b)}
tan(a - b) = ?
{tan(a) - tan(b)} / {1 + tan(a)tan(b)}
sin(2a) = ?
2sin(a)cos(a)
cos(2a) = ?
cos^2(a) - sin^2(a), 1 - 2sin^2(a), 2cos^2(a) - 1
tan(2a) = ?
{2tan(a)} / {1 - tan^2(a)}
sin(a/2) = ?
+- sqrt({1 - cos(a)} / {2})
cos(a/2) = ?
+- sqrt({1 + cos(a)} / {2})
tan(a/2) = ?
+- sqrt({1 - cos(a)} / {1 + cos(a)}), {sin(a)} / {1 + cos(a)}, {1 - cos(a)} / {sin(a)}
sin^2(x) = ?
1/2(1 - cos(2x))
cos^(2x) = ?
1/2(1 + cos(2x))
tan^2(x) = ?
{1 - cos2x} / {1 + cos2x}
cos(a)cos(b) = ?
1/2(cos(a + b) + cos(a - b))
sin(a)sin(b) = ?
1/2(cos(a - b) - cos(a + b))
cos(a)sin(b) = ?
1/2(sin(a+b) - sin(a-b))
sin(a) + sin(b) = ?
2sin({a + b}/{2})cos({a - b}/{2})
sin(a) - sin(b) = ?
2cos({a + b}/{2})sin({a - b}/{2})
cos(a) + cos(b) = ?
2cos({a+b}/{2}) cos({a-b}/{2})
cos(a) - cos(b) = ?
-2sin({a + b}/{2})sin({a - b}/{2})