Y1 is the simplest parabola. Its vertex is at (0,0) and it passes thru (2,4). This is enough info to conclude that y1 = x^2.
y4, the lower red graph, is a bit more of a challenge. We can easily identify its vertex, which is (-4,0), and several points on the grah, such as (2,-3).
Let's try this: assume that the general equation for a parabola is
y-k = a(x-h)^2, where (h,k) is the vertex. Subst. the known values,
-3-(-4) = a(2-0)^2. Then 1 = a(2)^2, or 1 = 4a, or a = 1/4.
The equation of parabola y4 is y+4 = (1/4)x^2
Or you could elim. the fraction and write the eqn as 4y+16=x^2, or
4y = x^2-16, or y = (1/4)x - 4. Take your pick! Hope this helps you find "a" for the other parabolas.
Answer:
£0.50
Step-by-step explanation:
t = one cup of tea
c = one piece of cake
t + c = £1.10
2t + c = £1.70
the cost increases by £0.60 (£1.70 - £1.10) when you order one more cup of tea which means that one cup of tea costs £0.60
substitute £0.60 into t + c = £1.10
£0.60 + c = £1.10
rearrange to get c = £1.10 - £0.60 = £0.50
so one piece of cake costs £0.50
Answer:
-5/7
Step-by-step explanation:
When you divide fractions, you flip the second fraction, then multiply.
So it becomes -25/28 x 4/5.
This equals -100/140 which reduces to -5/7.
Answer:
1423/33
Step-by-step explanation:
Let x = 43.121212.........
Two digits are repeating after decimal point. So multiply both sides by 100
100x = 4312.1212 --------------(I)
<u> x = 43.1212 </u> -----------(II) { subtract equation (II) form (I)}
99x = 4269
x= 4269/99 {reduce to simplest form by giving by 3rd table}
x = 1423/33
