The angle of the roof on Wendy's dollhouse is 56 degrees she built a scale model of the dollhouse with a scale ratio of 1 to 4 what is the measurement of the angle of the roof of the model?
Answer: 14
OK, so the graph is a parabola, with points x=0,y=0; x=6,y=-9; and x=12,y=0
Because the roots of the equation are 0 and 12, we know the formula is therefore of the form
y = ax(x - 12), for some a
So put in x = 6
-9 = 6a(-6)
9 = 36a
a = 1/4
So the parabola has a curve y = x(x-12) / 4, which can also be written y = 0.25x² - 3x
The gradient of this is dy/dx = 0.5x - 3
The key property of a parabolic dish is that it focuses radio waves travelling parallel to the y axis to a single point. So we should arrive at the same focal point no matter what point we chose to look at. So we can pick any point we like - e.g. the point x = 4, y = -8
Gradient of the parabolic mirror at x = 4 is -1
So the gradient of the normal to the mirror at x = 4 is therefore 1.
Radio waves initially travelling vertically downwards are reflected about the normal - which has a gradient of 1, so they're reflected so that they are travelling horizontally. So they arrive parallel to the y axis, and leave parallel to the x axis.
So the focal point is at y = -8, i.e. 1 metre above the back of the dish.
Answer:
First question: Choice A
second question:Choice D
Third question: Choice c
Fourth question: Choise b
5th Question: choice b
The answer for your question is A
Answer:
q= -4
Step-by-step explanation:
First, simplify 4x+2y=5
2y=-4x+5
y=-2x+5/2
q+2 has to equal to -2
q = -4
