A parabola has x-axis intercepts 6 and -3, and passes through the point (1,10). Find the equation of the parabola.
1 answer:
Answer:
y=-1/2 x^2+3/2 x+9
Step-by-step explanation:
The equation of parabola is:
y=ax^2+bx+c
We know that parabola has three poibts
(6,0),(-3,0) and (1,10).
So we put these three points in equation:
a*36+b*6+c=0......(1)
a*9-3b+c=0........(2)
a+b+c=10........(3)
(1)-(2) we have:
27a+9b=0.....(4)
(2)-(3) we have:
8a-4b=-10.....(5)
4(4)+9(5) we got:
180a=-90
a=-1/2
From (4) we got: b=27/18=3/2
From (3) we got: c=10+1/2-3/2=9
So equation is:
y=-1/2 x^2+3/2 x+9
You can see the picture of parabola through three points.
You might be interested in
Answer:
Step-by-step explanation:
In order to add or subtract numbers in scientific notation, the powers of ten must have the same exponent. In this caes the diameter of an average human body cell is a power of -4 and the diameter of a plant cell is a power of -3. In order to add them, we can move the decimal over for the body cell diameter:
Add the two values:
The sum of the inner angles of any triangle is always 180°, i.e. you have
In the particular case of an equilater triangle, all three angles are the same, so
and the expression becomes
which implies
So, if you rotate the triangle with respect to its center by 60 degrees, the triangle will map into itself. In particular, if you want point A to be mapped into point B, you have to perform a counter clockwise rotation of 60 degrees with respect to the center of the triangle.
Of course, this is equivalent to a clockwise rotation of 120 degrees.
Finally, both solutions admit periodicity: a rotation of 60+k360 degrees has the same effect of a rotation of 60 degrees, and the same goes for the 120 one (actually, this is obvisly true for any rotation!)