# C4 Flashcards Preview

## X OCR MEI C4 maths > C4 > Flashcards

Flashcards in C4 Deck (21)
1
Q

How would a partial factor which has a (x-1)(x^2+4) denominatior be written ?

A

A/(x-1) + (Bx-c)/(x^2+4)

2
Q

If when doing the general binomial expansion and the constant is not 1 how can it be written?

A

(a+b)^n = a^n × (1+(b÷a))^n

3
Q

What is cosec

A

1÷ sin

4
Q

What is sec

A

1÷cos

5
Q

What is cot

A

1÷tan

6
Q

What are the inverse trig identities to know?

A

Tan^2 +1 = sec^2

Cot^2+1=cosec^2

7
Q

Sin2x=

A

2sinxcosx

8
Q

What does cos(2x) equal

A

Cos^2 -sin^2
1-2sin^2
2cos^2 -1

9
Q

How would you write sin(75) in surd form

A

write is as sin(30+45), then expand and simplify.

10
Q

write 5cosσ-12sinσ in the form Rcos(σ+θ)

A
```R(cosσcosθ-sinσsinθ)
Rcosθ=5                   Rsinθ=12
θ=67.4
R=the root of 5^2 plus 12^2 which is 13
13cos(θ+67.4)```
11
Q

How do you differentiate a parametric equation?

A

Differentiate the different parts and use the chain rule to find dy/dx.
It is usually the differential of y divided by the differential of x.

12
Q

what is the formula for the volume of revolution around the x axis?

A

intergrate pi*(y^2) for x axis

Use pi*(x^2) for the y axis.

13
Q

in the formula booklet for the plane going through a point, what does the a and n mean?

A

a is a point that is on the plane. n is a normal to the plane.
the coefficeints of the plane are the values of the perpendicular.

14
Q

how can you tell that two planes are parallel?

A

The coefficients will be the same.

15
Q

how do you find the angle between 2 vectors?

A

cos theta = (a dot b) / |a||b|

16
Q

what does the cross product give?

A

a vector that is perpendicular to 2 different vectors.

17
Q

What is the parametric equation of a circle?

A

X= a+rcos⊝
Y= b+rsin⊝
r is the radius and the centre is (a,b)

18
Q

How would the fraction with denominatior (x-1)(x+2)² be written in partial fractions?

A

A/(x-1) + B/(x+2) + C/(x+2)²

19
Q

For what values of x are binomial expansions valid?

A

For (1+x)ª |x|

20
Q

What is a vector perpendicular to a plane?

A

One with the same coefficients of the plane.

21
Q

How do you find the angle between two planes?

A

Angle between the normals