Respuesta :
The angle between the vectors t and u is 45°. And the vector t and vector w are orthogonal to each other.
What is a vector?
The quantity which has magnitude, direction and follows the law of vector addition is called a vector.
The vectors are given below.
t = −5i + 2j, u = −3i + 7j, and v = 8i + 20j
Part A: Then the angle between vectors t and u will be
[tex]\cos \theta = \dfrac{\overrightarrow{a} \cdot \overrightarrow{b}}{|\overrightarrow{a}| + |\overrightarrow{b}|}[/tex]
Then we have
cos θ = [(−5i + 2j)(−3i + 7j)] / [√{(-5²) + 2²} + √{(-3)² + 7²}]
cos θ = 1 / √2
θ = 45°
Part B: c is a scalar
If [tex]\rm \overrightarrow{\rm v} = (a, b)[/tex], then [tex]\rm c\overrightarrow{\rm v} = c(ca, cb)[/tex]
Let c = 2, then we have
[tex]\overrightarrow{\rm w} = c\overrightarrow{v}\\\\\overrightarrow{\rm w} = (2*8, 2*20)\\\\\overrightarrow{\rm w} = (16, 40)[/tex]
Part C: Use the dot product to determine if t and w are parallel or orthogonal.
[tex]\overrightarrow{\rm t} \cdot \overrightarrow{\rm w} = (-5, 2)(16, 40)\\\\ \overrightarrow{\rm t} \cdot \overrightarrow{\rm w} = -5*16+ 2*40\\\\ \overrightarrow{\rm t} \cdot \overrightarrow{\rm w} = -80+ 80\\\\ \overrightarrow{\rm t} \cdot \overrightarrow{\rm w} = 0[/tex]
More about the vector link is given below.
https://brainly.com/question/13188123
#SPJ1