Graph the quadratic variation if g(x) varies directly with x2, and g(x) = 50 when x = 10.

Question

lovelyanna · Answer

attachment

lovelyanna · Answer

@whpalmer4 
either 1st or 3rd one?

campbell_st · Answer

you have 

$$y = ax^2$$

so substitute x = 10 and y = 50 to find a

then you have the equation, and can match it to a graph.

lovelyanna · Answer

Hmm.. a bit confusing.. would it be 1st one?

campbell_st · Answer

well when you get the value of a, 

use a table of values

x = 0   y = ?

x = 1   y = ?

x = 2   y = ?

and its not the 1st graph

anonymous · Answer

its 2

lovelyanna · Answer

It is..?

campbell_st · Answer

there you go... wait long enough... someone always gives an answer.... no need to learn anything

lovelyanna · Answer

wait.. I don't get, can you explain more please?

lovelyanna · Answer

Can someone please explain..?

campbell_st · Answer

well you know its direct variation so 

$$y = ax^2$$

to find a, then use the given information 

x = 10, y = 50

$$50 = a(10)^2$$

whats the value of a...?

campbell_st · Answer

to make it easier

$$50 = a \times 100$$

whats the value of a..?

lovelyanna · Answer

a = 0.5

campbell_st · Answer

yep... so use a some simple values 

x = 0     y = 0.5 (0)^2 = 0   so you have a point (0,0)

x = 1    y = 0.5 (1)^2  = 0.5                               (1, 0.5)

x = 2    y = 0.5 (2)^2  = 2                                  (2, 2)

x = 3   y = 0.5(3)^2  = 4.5                                  (3, 4.5)

look for the graph with those points

campbell_st · Answer

yep... where is your question..

lovelyanna · Answer

Oh, I get it now! thanks :)

lovelyanna · Answer

thats all