Posted by **j** on Thursday, May 17, 2012 at 9:19am.

determine the angle between the planes 2x + 2y + 7z = 8 and 3x - 4y + 4z = 5

- Calculus -
**Reiny**, Thursday, May 17, 2012 at 9:42am
let Ø be the angle between their normals

(2,2,7)∘(3,-4,4) = √57√41cosØ

cosØ = (6 - 8 + 28)/(√57√41)

Ø = appr. 57.5°

so the two planes form an angle of 180-57.5 or 122.5°

## Answer this Question

## Related Questions

- Math - Someone please explain these! The angle between two planes is defined as ...
- Math - Someone please explain these! The angle between two planes is defined as ...
- Math - Someone please explain these! The angle between two planes is defined as ...
- Calculus - determine the angle between the planes 2x + 2y + 7z = 8 and 3x - 4y...
- Calculus - Use normal vectors to determine the intersection, if any, for each of...
- Trigonometry - Cosine of angle - What is the cosine of the angle between two ...
- Linear Algebra 2 - This is another question I can't figure out. Given planes ...
- multivariable calculus - Consider the surface given by the equation: 2x2 - 3z2...
- Calc. - Use normal vectors to determine the intersection, if any, for each of ...
- Calc. - Use normal vectors to determine the intersection, if any, for each of ...