Thread: intersection

From the point drawn normals to the two planes and have the equations and . A plane containing the two normals. Determine the intersection, and . (ON-system.) ima answer the intersection

how shall i take dot product on this one?

Hey Petrus.

If two planes intersect then they are equal to each other.

Can you solve the linear system corresponding to the intersection?

(Hint: for the third plane the normal of this plane will correspond to the cross product of the two other normal vectors).

Sorry idk what to do on this problem.. I cant solve the equation

Recall that a plane in three dimensions has the form ax + by + cz = d for some constants a,b,c,d.

Now you just have to solve a linear system with three of these equations where you solve for x given the system Ax = b.

Do u mean like
Y=8+2z?
wha i thought i need to find the third plane to solve the linear equation

That is one equation of a plane where Y - 2z = 8 where a = 0, b = 1, c = -2 and d = 8 in this particular example.

I serious dont understand this one, any tips what i should read to get this... Im clueless

Originally Posted by Petrus

From the point drawn normals to the two planes and have the equations and . A plane containing the two normals. Determine the intersection, and . (ON-system.) ima answer the intersection

Actually I have not idea exactly what that says.
I think it means that is not on either plane: .

The plane contains the and the two normals

If that is not what you are asking, try to clear it up please.

From the plane P draw the normal to the both i1 and i2 that have the equation x-y+5z=2 and y-2z=8. A plane i3 got the both normal. Decide the intersection between i1,i2 and i3 ( on bas)
Thats My translate sorry i hope u understand but the answer shall be
111/14,47/7,-9/14

Originally Posted by Petrus

From the plane P draw the normal to the both i1 and i2 that have the equation x-y+5z=2 and y-2z=8. A plane i3 got the both normal. Decide the intersection between i1,i2 and i3 ( on bas)
Thats My translate sorry i hope u understand but the answer shall be
111/14,47/7,-9/14

Again, if we understand each other, then solve

Yes

Did you take Plato's advice and solve the linear system?

If you need to check your work use a program like Octave to do so which is free and you can download GUI octave for the MATLAB style window.

If i understand right then x =-3/2 then ima solve rest somehow ? Is that program big? I got a really cheap pc so and its alredy so slow

Since this is a 3x3 system with Ax = b we know that x = A^(-1)b and there are many websites that do matrix multiplication and inverse calculations.

Here is one of them:

3x3 Inverse Matrix Calculator & Calculation

3x3 Matrix Multiplication Calculator, 3x3 Matrices Calculation Formula