Answer:
y = 8x + 19.
Step-by-step explanation:
point-slop form
Step-by-step explanation:
5x^2+2x=1
5x^2+2x-1=0
x=-b+/-√b^2-4ac÷2a
x=-2+/-√-2^2-(4×5×-1)÷2×5
x=-2+/+√4--20÷10
x=-2+/-√24÷10
x=-2+√24÷10 or -2-√24÷10
x=-2+4.9÷10 or -2-4.9÷10
x=2.9÷10 or -6.9÷10
x=0.29 or -0.69
Answer:
200 miles
Step-by-step explanation:
1 inch = 100 miles
2 inch = 2*100 = 200 miles
The lines are
i) y=-x+6
ii) y=2x-3
The solution of the system of equations is found by equalizing the 2 equations:
-x+6=2x-3
-2x-x=-6-3
-3x=-9
x=-9/(-3)=3
substitute x=3 in either i) or ii):
i) y=-3+6=3
ii) y=2(3)-3=6-3=3
(the result is the same, so checking one is enough)
This means that the point (3, 3) is a point which is in both lines, so a solution to the system.
In graphs, this means that the lines intersect at (3, 3) ONLY
Answer: The graph where the lines intersect at (3, 3)
F(x) = 18-x^2 is a parabola having vertex at (0, 18) and opening downwards.
g(x) = 2x^2-9 is a parabola having vertex at (0, -9) and opening upwards.
By symmetry, let the x-coordinates of the vertices of rectangle be x and -x => its width is 2x.
Height of the rectangle is y1 + y2, where y1 is the y-coordinate of the vertex on the parabola f and y2 is that of g.
=> Area, A
= 2x (y1 - y2)
= 2x (18 - x^2 - 2x^2 + 9)
= 2x (27 - 3x^2)
= 54x - 6x^3
For area to be maximum, dA/dx = 0 and d²A/dx² < 0
=> 54 - 18x^2 = 0
=> x = √3 (note: x = - √3 gives the x-coordinate of vertex in second and third quadrants)
d²A/dx² = - 36x < 0 for x = √3
=> maximum area
= 54(√3) - 6(√3)^3
= 54√3 - 18√3
= 36√3.
