# Difference between revisions of "C++:3D Exercises"

(→Cross Product) |
(→Vector Length) |
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Line 133: | Line 133: | ||

cout << length(A)<< endl; | cout << length(A)<< endl; | ||

cout << length(B)<< endl; | cout << length(B)<< endl; | ||

+ | return 0; | ||

+ | } | ||

+ | ]]></prog> | ||

+ | |||

+ | <answer><![CDATA[ | ||

+ | #include <math.h> | ||

+ | #include <iostream> | ||

+ | using namespace std; | ||

+ | |||

+ | float length(float a[3]){ | ||

+ | float r=sqrt(a[0]*a[0]+a[1]*a[1]+a[2]*a[2]); | ||

+ | return r; | ||

+ | } | ||

+ | |||

+ | int main(int argc, char **argv) | ||

+ | { | ||

+ | float A[]={1,0,1}; | ||

+ | float B[]={1,1,2}; | ||

+ | cout << length(A)<< endl; | ||

+ | cout << length(B)<< endl; | ||

+ | return 0; | ||

+ | } | ||

+ | ]]></answer> | ||

+ | </question> | ||

+ | |||

+ | ==Normal to a plane== | ||

+ | <question> | ||

+ | Find the unit normal to the plane that contains the three points given. | ||

+ | <prog><![CDATA[ | ||

+ | #include <math.h> | ||

+ | #include <iostream> | ||

+ | using namespace std; | ||

+ | |||

+ | float length(float a[3]){ | ||

+ | float r=sqrt(a[0]*a[0]+a[1]*a[1]+a[2]*a[2]); | ||

+ | return r; | ||

+ | } | ||

+ | |||

+ | int main(int argc, char **argv) | ||

+ | { | ||

+ | float A[]={1,0,1}; | ||

+ | float B[]={1,1,2}; | ||

+ | float C[]={0,1,3}; | ||

return 0; | return 0; | ||

} | } |

## Revision as of 14:08, 23 November 2011

## Dot Product

Calculate the dot product of two vectors.
Fill in the details in the function **dotproduct**

Wikipedia includes a good article on dot products. http://en.wikipedia.org/wiki/Dot_product#Definition

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## Cross Product

Calculate the cross product of two vectors.
Fill in the details in the function **crossproduct**

Wikipedia includes a good article on cross products. http://en.wikipedia.org/wiki/Cross_product#Coordinate_notation

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## Vector Length

Calculate the magnitude of a vector.
Fill in the details in the function **length**

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## Normal to a plane

Find the unit normal to the plane that contains the three points given.

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