BangOn wrote:
maaadhu wrote:
manjusu wrote:
We can also solve this problem as follows
the equation given in the question is
y= 3x^2 + 5x+1
=> y = x(3x + 5) + 1 (Taking x as common)
from the above equation we can say that m(slope) = 3x + 5
Therefore whichever equation in the answer choices has same slope as above, is our answer.
Because two lines having same slope are parallel to each other and does not intersect.
C. y= 3x^2 + 5x+2
=> y= x(3x + 5) + 2
m= 3x +5
Cheers,
Suman.
the equation given in the question is
y= 3x^2 + 5x+1
=> y = x(3x + 5) + 1 (Taking x as common)
from the above equation we can say that m(slope) = 3x + 5
Therefore whichever equation in the answer choices has same slope as above, is our answer.
Because two lines having same slope are parallel to each other and does not intersect.
C. y= 3x^2 + 5x+2
=> y= x(3x + 5) + 2
m= 3x +5
Cheers,
Suman.
Manju,
concept of slope for lines & parabolas are different. Bunuel, please correct if I am wrong. Also please help to solve this problem if its a GMAT type question.
The general form of parabolic equ. is y^2= 4ax which implies the axis is x or x^2 = 4ay where axis is y.
We have a similar form as x^2 = 4ay.
here the vertex is origin.
So if we have same values of x and y but constant term changes then we will have parallel parabolas.
This is same as for straight line which are parallel for different values of constant term c
ax + by +c1 = 0 and ax +by+ c2 =0
We have quadratic equations. These equations when drawn give parabolas, not lines. The question is: which of the following parabolas does not intersect with the parabola represented by y=3x^2+5x+1.
This CANNOT be transformed to the question: "which of the following parabolas is parallel to the parabola represented by y=3x^2+5x+1." In the wast majority of cases the word "parallel" is used for lines. Well, we can say that concentric circles are parallel, BUT GMAT, as far as I know, uses this word ONLY about the lines. Next, the word "parallel" when used for curves (lines, ...) means that these curves remain a constant distance apart. So strictly speaking two parabolas to be parallel they need not only not to intersect but also to remain constant distance apart. In this case, I must say that this cannot happen. If a curve is parallel (as we defined) to the parabola it won't be quadratic: so curve parallel to a parabola is not a parabola.