Answer:
The perpendicular line 4x − 5y = 20 has a slope of 4/5 and as such, the slope of the required line = -5/4
(y - 3)/(x + 4) = -5/4 simplify to get the required equation: 5x + 4y + 8 = 0
The angle between two vectors is:
CosФ = u - v / Magnitude(u) x magnitude(v)
Magnitude of u = SQRT(7^2 + -2^2) = SQRT(49 +4) = SQRT(53)
Magnitude of v = SQRT(-1^2 +2^2) = SQRT(1 +4) = SQRT(5)
u x v = (7 x -1) + (-2 x 2) = -7 + -4 = -11
cosФ = -11 / sqrt(53) x sqrt(5)
cosФ = -11sqrt265) / 265
Ф =cos^-1(-11sqrt265) / 265)
Ф=132.51 degrees.
Answer:
1.A,B,C,D
2. AB, CD
3. AC, BD
4. Line AD (don't take my word for this one)
Step-by-step explanation:
