## Calculus 3 Resources Matrices question. PLSSSSS HELP.

4. Let n≥2, let A and B b en×n matrices and let On be the n×n matrix with every entry 0. (b) Suppose that A2 = On. Show that In − A is invertible, and that (In − A)-1 = In + A. (c)...

I have 7-9 of these answers correct, but it does not tell me which ones are incorrect (although I have a hunch). The following are the problems and the answers are in bold that I have given.   -8x2+5y2-z2=0... Suppose U = <2,3,4> Then:

<4,5,3> makes a (right, obtuse, or acute) with u. <5,-1,2> makes a (right, obtuse, or acute) with u. <-8,0,4> makes a (right, obtuse, or acute) with u. <3,2,-3>... What are the coordinates of the point where he makes his turn?

Gandalf the Grey started in the Forest of Mirkwood at a point with coordinates (−3,3) and arrived in the Iron Hills at the point with coordinates (−1,6). If he began walking in the direction of the... Let V = <1, 3, 3>. Find a unit vector for this.

I have 1/sqrt(10), 3/(sqrt(10)), 3/sqrt(10). I cannot understand why this is not the answer. It is pointing in the same direction. C-(-4,2,4). Find the distance between the point (x,y,z) and C.

I had tried the points (0,0,0)-(-4,2,4) and then use the distance formula, but that has not worked. Then I tried (1,1,1), but that also did not work. I am lost. Any help is needed. Find the length of ->OR.

(We are talking about vectors.   R = (4, 5, 5).   Then it has,   ||->OR|| = _____.   I'm not sure how you find OR if you do not have what O is...

While a planet P rotates in a circle about its sun, a moon M rotates in a circle about the planet, and both motions are counterclockwise in the same plane. Let's call the distance between M and P... Find the equation of a sphere if one of it's diameters has endpoints (-10,0,-6) and (4, 14, 8).

I have written:   (x+3)2+(y-7)2+(z-1)2-sqrt(588)/2 = 0. But it is marked incorrect.

I had put the equation as:   (x-5)^2+(y-3)^2+(z+6)^2   However it was viewed as incorrect. Also they had that it equaled zero.   equation input =... Find the equation of the sphere centered at (−1,10,2) ( − 1 , 10 , 2 ) with radius 4.

Find the equation of the sphere centered at (−1,10,2) ( − 1 , 10 , 2 ) with radius 4.   ___________________ = 0   Give an equation which describes the intersection of this... Double integral - calculating area

Calculate the area of the region bounded by the two curves, y = 4 - x2 and y = x + 2.   The answer is meant to be 9/2 but I just cannot get it!!! Maybe my bounds are incorrect...... find volume using triple integrals

a triple integral in spherical coordinates to find the volume of the solid bounded by the surface s z=0, z=a, x2+y2+z2= 4a2