# C3 Formulas

• Created by: sarxhj
• Created on: 26-01-15 10:23
cosecx
1/sinx
1 of 36
secx
1/cosx
2 of 36
cotx
1/tanx
3 of 36
Trig Indentity 1
cos^2x + sin^2x = 1
4 of 36
Trig Identity 2
sec^2x = 1 + tan^2x
5 of 36
Trig Identity 3
cosec^2x = 1 + cot^2x
6 of 36
sin (A + B)
= sinA cosB + cosA sinB
7 of 36
sin (A - B)
= sinA cosB - cosA sinB
8 of 36
cos (A + B)
= cosA cosB - sinA sinB
9 of 36
cos (A - B)
= cosA cosB + sinA sinB
10 of 36
tan (A + B)
= tanA + tanB / 1 - tanA tanB
11 of 36
tan (A - B)
= tanA - tanB / 1 + tanA tanB
12 of 36
sin2A
= 2sinA cosA
13 of 36
cos2A
= cos^2A - sin^2A OR =2cos^2A - 1 OR = 1 - 2sin^2A
14 of 36
tan2A
= 2tanA / 1 - tan^2A
15 of 36
asinx ± bcosx
= Rsin (x ± a)
16 of 36
acosx ± bsinx
= Rcos (x ∓ a)
17 of 36
sinA + sinB
= 2sin (A + B / 2) cos (A - B / 2)
18 of 36
sinA - sinB
= 2cos (A + B / 2) sin (A - B / 2)
19 of 36
cosA + cosB
= 2cos (A + B / 2) cos ( A - B / 2)
20 of 36
cosA - cosB
= -2sin (A + B / 2) sin (A - B / 2)
21 of 36
lnx + lny
= ln(xy)
22 of 36
lnx - lny
= ln(x/y)
23 of 36
lnx^k
= k lnx
24 of 36
e^lnx
= x
25 of 36
ln (e^x)
= x
26 of 36
when y=e^x
dy/dx = e^x
27 of 36
when y=lnx
dy/dx = 1/x
28 of 36
when y=sinx
dy/dx = cosx
29 of 36
when y=cosx
dy/dx = -sinx
30 of 36
when y=tanx
dy/dx = sec^2x
31 of 36
Product rule
y=u(x)v(x) then dy/dx = u dv/dx + v du/dx
32 of 36
Quotient rule
y=u(x) / v(x) then dy/dx = v du/dx - u dv/dx // v^2
33 of 36
y = cosecx
dy/dx = -cosecx cotx
34 of 36
y = secx
dy/dx = secx tanx
35 of 36
y = cotx
dy/dx = -cosec^2x
36 of 36

## Other cards in this set

1/cosx

secx

1/tanx

### Card 4

#### Front

cos^2x + sin^2x = 1

### Card 5

#### Front

sec^2x = 1 + tan^2x