The Student Room Group
Reply 1
For what value of x does the line cross the y-axis?
For what value of y does the line cross the x-axis?
Gradient = change in y/change in x- use the coordinates calculated in a)
Reply 2
1)

rearrange to nice form:

2y - x = 4
2y = x + 4
y = 0.5x + 2

so, y = 0 when x = -4
x = 0 when y = 2

(by plugging the numbers in)

gradient, uh, well, by converting the equation into the above format we know the grad is a half. or, you can take the two points you know, (-4,0) and (0,2), and then find change in y over change in x.
Reply 3
2)

angles in same segment... so it's 40 degrees.

opp. angles in cyclic quad... so it's 180 - 40 = 140 degrees.

since it's a tangent, BAD & BCD are right angles. ABCD is a quadrilateral -> internal angles = 360. 360 - 90 - 90 - 2(40) = 100
Reply 4
Question 2
a) i) Angles in a segment rule. Look at the angle already drawn in. You don't have to do any calculations as it says 'write down...'

ii) Look at the quadrilateral with angles x and y in. There is a rule for quadrilaterals in a circle. As this is a one mark question, you don't have to do very much working out at all, just thinking.

b) What's angle ABD? Look at the angle you already know, and the fact that line AD is a tangent. Now you should know what CBD is. Add them together...
Reply 5
Chewwy got there first! Sorry :rolleyes:
hearthethunder
Yeah OK having trouble scraping a B here, maths being my weakest subject.. but anyway I have two questions here where I got a grand total of 0 marks on both. Can someone help me - HOW do you do these questions?! :

Question 1
Question 2



Just for the sake of reiteration of what everyone else has said:

Question 1

2y - x = 4

Point A is on the x-axis, ie at a point where y=0.
Substitute y=0.
2(0) - x = 4,
-x = 4,
x=-4.
A(-4,0).

Similarly, Point B is on the y-axis, ie at a point where x=0.
Substitute x=0.
2y - (0) = 4
2y = 4
y = 2
So B(0, 2).


In a linear equation, that is, one in the form of y=mx + c, the gradient is m, and can be read off.

So we desire the given equation of the line, in this form - a simple rearrangement.

Given 2y - x = 4
2y = x + 4
y = 1/2(x + 4)
y = 0.5x + 2

So, the gradient m = 0.5.

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