(Please help!) The diagram shows a set of coordinate axes superimposed on the cross section of a sloping roof of height, h metres and width w metres. The equation of one half of the cross section is y= -0.7x+1.9. a) What is the equation of the other half of the cross section? b) What is the width of the roof, w, to the nearest tenth of a metre? c) State the domain and range of each function that states each half of the roof.

Question

anonymous · Answer

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anonymous · Answer

a) The answer is 0.7x + 1.9 but why? b) The answer is w= 5.4 m, and why?

anonymous · Answer

The slopes of the two sides of the roof are just straight lines. So with line h at the x=0, the slope will be negative when the rise/run is negative and positive when the rise/run is positive.

For the other one, let y=0 so x=-1.9/-.7 or 1.9/.7 for the other equation let y=0 so x=-1.9/.7 the distance between the two points is 3.8/.7 or 5.4