maths Flashcards
to learn formula
1
Q
sin (A + B)
A
sin A cos B + cos A sin B
2
Q
sin (A – B)
A
sin A cos B – cos A sin B
3
Q
cos (A + B)
A
cos A cos B – sin A sin B
4
Q
cos (A – B)
A
cos A cos B + sin A sin B
5
Q
tan (A + B)
A
tan A+ tan B
1 -tan A tan B
6
Q
tan (A – B)
A
tan A-tan B
1 +tan A tan B
7
Q
cot (A + B)
A
cot A cot B -1
cot A +cot B
8
Q
cot (A – B)
A
cot A cot B+ 1
cot B- cot A
9
Q
sin 2A
A
= 2 sin A cos A =
2 tan A
1+ tan^2 A
10
Q
cos 2A
A
cos^2 A – sin^2 A = 1 – 2 sin^2
A = 2 cos^2 A – 1
1 – tan^2 A
1+ tan^2 A
11
Q
tan 2A
A
2 tan A
1 – tan^2 A
12
Q
cos 3A
A
4cos^3 A – 3cos A
12
Q
sin 3A
A
3sin A – 4sin^3A
13
Q
tan 3A
A
3 tanA – tan^3 A
1 – 3tan ^2A
14
Q
cos A + cos B
A
2cos (a+b)/2 sin(a-b)/2
