The profile of a section of roller coaster track is given by the equation h(x) = (2500+500sin(10pix))/x , X E [100,400], where h is the height of the track, in metres, and x is horizontal position, in metres.
a) Calculate the steepness (slope) of the track at the initial horizontal position.

the reason why your question keeps getting deleted because this is not a school related question : )

i will answer your question though.

i never tried church's

so a parallelogram is just like a square base times height. multiply 40 and 39 to get 1560 inches.

a triangle is base times height divided by two. so multiply 7.9 and 5 and then divide it by 2 to get 19.75inches.

the kite can be split into two separate triangles and added together to get the total area. 30 x 4 /2 which equals 60. make sure to double it for the two triangles making 120.