need help with question b (3d geom, planes and vectors)

[umricky]

as you can see i tried doing it but im not sure if i did it correctly. i feel like i messed up when i converted my vector equation of the plane to the cartesian form.

pls let me know if i did it correctly.

 

[blamocur]

I agree that 3x+4z = 0 even though you computation of $\overrightarrow n$ seems to have one wrong sign. But I don't understand how you compute $\cos\theta$, and the compute value seems wrong to me.

 

[umricky]

I agree that 3x+4z = 0 even though you computation of $\overrightarrow n$ seems to have one wrong sign. But I don't understand how you compute $\cos\theta$, and the compute value seems wrong to me.

what did i do wrong when i tried to find n? bc rn i multiplied 2 direction vectors.

to find cos i used the equation to find the angle between two vectors using the dot product

 

[blamocur]

what did i do wrong when i tried to find n?

I told you that you got one of the signs wrong, it should be 3600, not -3600.

to find cos i used the equation to find the angle between two vectors using the dot product

Using dot product of what?