Top answers

What is the angle between the position vectors a and b, where a = (6i - j + 3k) and b = (-4i + 2j + 10k)?

cos( AOB ) = a.b /(| a | x | b |) a.b = (6i - j + 3k) . (-4i + 2j + 10k) = (6 x -4) + (-1 x 2) + (3 x 10) = -24 + -2 + 30 = 4 (| a |)^2 = 6^2 + (-1)^2 + 3^2 = 36 + 1 + 9 = 46 -> | a | = 46^(1/2) (| b |)^2...
DH
Answered by David H. • Maths tutor
6815 Views

Solve the simultaneous equations 3x + 4y = 17 and 4x + y = 14

Eq1: 3x + 4y = 17 Eq2: 4x + y = 14 Eq2 x 4: 16x + 4y = 56 Subtract Eq1 from this to isolate x: 16x + 4y - 3x - 4y = 56 - 17 Simplify: 13x = 39 Solve for x: x = 3 Substitute x into Eq1: 3(3) + 4y = 17 9 + 4y ...
DH
Answered by David H. • Maths tutor
9303 Views

What is the median, upper quartile and lower quatile. How do we find them?

The easiest way to explain this would be to use an examplar question. For example: Ben is given a sequence of numbers and is told to find the median, lower quartile and upper quartile. 1,4,5,6,8,9,11,12,14,1...
DB
Answered by Daniella B. • Maths tutor
19588 Views

What is the fraction of blue beads?

A tin contains red, white and blue beads in the ratio red:white:blue = x:2x:x^2 First we should find the total number of beads in the tin: x + 2x + x^2 = 3x + x^2 The number of blue beads is x^2 So the fract...
RB
Answered by Rheanne B. • Maths tutor
7584 Views

How many people chose A?

In a survey people had to choose either A, B, C or D. The percentage of people that chose B, C and D are shown here: B- 25% C- 35% D- 30% You are also told that 150 people chose B. How many chose A? So first...
RB
Answered by Rheanne B. • Maths tutor
6506 Views