Ski Jump HELPPPP

I want to design this:

The ski jump starts at a height of h feet and finishes at a launch point height of eh feet, where height is represented by the variable y. From the start (x = 0) to the launch point, the ski jump extends a horizontal distance of d feet. A skier using the jump will begin horizontally and will fly off the end at a sa degree angle from the horizontal. Develop the set of equations to determine the four coefficients of a cubic polynomial y = f(x) for the side
view of the ski jump that meets the specifications above. Write a script to compute and display these coefficients, using methods described in class to solve a set of linear equations.

I want to plot this as well.

Here's my code, its effed up though I need help on assigning these values because every try is a failure!

A = [ 0 0 0 1 ];

d^3 d^2 d 1;

0 0 1 0;

3*d^2 2*d 1 0];

b = [100; 10; 0; tan(30*pi/180)];

format short e;

c = A\bx == 0:d;

y = polyval(c,x);

plot(x,y)

Answer 1

[Walter Roberson]

Try removing the ']' from the first line. And make sure you define d before that first line.

You need to define your variable "bx".

Why are you comparing A\bx to the vector of integers from 0 to d ?

Answer 2

[Leah]

I'm pretty sure you want to set up A as the system of linear equations like this

A=[0 0 0 1; 1 1 1 1; 0 0 1 0; 3 2 1 0]
b = [100; 10; 0; tan(30*pi/180)];
c=A\b
d=4*pi
x=1:.1:d
y = polyval(c,x);
plot(x,y)

It also seems that x=0:d, the range you want to evaluate your polynomial over. I'm not sure what that is so i made up some numbers.

Like Walter said always make sure you define variable in the right order. You can't use them until you create them.

[Rahul Karelia]

Thank you leah, can u show what kind of Graph you get when you run this Code ?

[Image Analyst]

It works, did you try it Rahul?

A = [0 0 0 1; 1 1 1 1; 0 0 1 0; 3 2 1 0]
b = [100; 10; 0; tan(30*pi/180)];
c = A\b
d = 4*pi
x = 1:.1:d
y = polyval(c,x);
plot(x,y, 'b-', 'LineWidth', 2);
xlabel('x', 'FontSize', 22);
ylabel('y', 'FontSize', 22);
title('y vs. x', 'FontSize', 22);
grid on;