All C4 Flashcards
1
Q
If y = a^x, what is dy/dx
A
(a^x)(ln a)
2
Q
What is a unit vector?
A
A unit vector is a vector which has magnitude (or modulus) 1 unit.
3
Q
What is the scalar product of two vectors?
A
a.b = (mod a)(mod b)(cosX)
Where X is the angle between a and b.
4
Q
If a and b are the position vectors of the points A and B what is the angle AOB?
A
cos AOB = (a.b)/(mod a)(mod b)
5
Q
Non-zero vectors a and b are perpendicular when…
A
a.b = 0
6
Q
If a and b are parallel, a.b =
A
a.b = (mod a)(mod b)
7
Q
What is the acute angle x between two straight lines?
A
cos X = Mod ( (a.b) / (mod a)(mod b) )
Where a and b are the direction vectors of the lines
8
Q
$ u (dv/dx) dx
A
uv - $ v (du/dx) dx
9
Q
2sinAcosB
A
sin(A+B) + sin(A-B)
10
Q
2cosAcosB
A
cos(A+B) + cos(A-B)
11
Q
2sinAsinB
A
- ( cos(A+B) - cos(A-B) )
