8. domain=hours
range=cost
it is a function because there is a y value for ever x
9. minutes =60, 120,180, 240 (domain)
calories= 360, 720, 1080, 1440 (range)
this is also a function
Remark
This is a very interesting question. Draw a line from the origin to where the upper right vertex of the square touches the line. That line has the property that the its equation is y = x. So the "solution" to the point of intersection is the solution of the two equations.
y = x (1)
3x + 4y = 12 (2)
Put x in for y in equation 2
3x + 4x = 12
7x = 12
x = 12/7
x = 1.714
y = 1.714
Problem A
<em><u>x intercept</u></em>
The x intercept occurs when y = 0
3x + 4(0) = 12
3x = 12 Divide by 3
x = 12/3
x = 4
the x intercept = (4,0)
<em><u>y intercept</u></em>
The y intercept occurs when x =0
3(0) + 4y = 12
4y = 12
y = 12/4
y = 3
y intercept = (0,3)
Problem B
x and y both equal 1.714 so they are also the length of the square's side.
Problem C
See solution above. x =y is the key fact.
x = y = 1.714
Step-by-step explanation:
the sum of all angles in a triangle is ALWAYS 180°.
and by using the word "congruent" : for angles that only means they are equally large.
we know the third angle.
so,
180 = P + Q + R = 2×P + 28.45
(because P = Q)
2×P = 151.55
P = Q = 151.55 / 2 = 75.775°
