Q 01/05

Slope is defined as rise over what?

A) Span

B) Run

C) Length

D) Height

Answer · why

B) Run

Run. Dividing the change up or down by the change across turns steepness into one number, so a slope of 2 means two units up for every unit along.

Q 02/05

What is the slope of the line through the points (1, 2) and (3, 14)?

A) 1/6

B) 6

C) 12

D) 24

Answer · why

B) 6

6. The line climbs 12 while moving only 2 across, and 12 ÷ 2 = 6; dividing the wrong way round, the classic slip, gives 1/6.

Q 03/05

Which letter is traditionally used for slope in the equation y = mx + b?

A) b

B) x

C) m

D) y

Answer · why

C) m

m. Nobody knows why that letter was chosen: the popular link to the French monter, 'to climb', has no evidence behind it, and Descartes, who was Frenc...

Q 04/05

What does a line with positive slope do as you read it from left to right?

A) It goes up

B) It goes down

C) It stays level

D) It goes straight up

Answer · why

A) It goes up

It goes up. A positive slope means y grows as x grows, and the bigger the number the steeper the climb; a slope below zero runs downhill instead.

Q 05/05

Where does the graph of y = 2x + 6 cross the y-axis?

A) At (0, 2)

B) At (0, 3)

C) At (0, 6)

D) At (6, 0)

Answer · why

C) At (0, 6)

At (0, 6). On the y-axis x is zero, so the 2x term vanishes and only the constant is left, which is why that constant is called the y-intercept.