Maths

There are 3 vectors:
p= 7i + 10j
q= 3i + 12j
r= -i +4j

Could you show me how to find the angle PQR. using the scalar product.

  1. 👍 0
  2. 👎 0
  3. 👁 182
  1. I will associate your vectors to have endpoints
    P(7,10), Q(3,12) and R(-1,4)
    then vector(PQ) = (-4,2)
    vector(QR) = (-4,-8)

    then PQ.QR = |PQ||QR|cos(theta), where theta is the angle between them
    16-16 = |PQ||QR|cos(theta)
    cos(theta) = 0
    theta = 90 degrees

    (notice the slope of lines PQ and QR are negative reciprocals of each other, so PQ and QR are perpendicular)

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics

    Three vectors are shown in the figure. Their magnitudes are given in arbitrary units. Determine the sum of the three vectors. Give the resultant in terms of (a) magnitude and (b) the angle within the positive x axis.

  2. physics-vectors

    If the magnitude of the sum of two vectors is greater than the magnitude of either vector, then: If the magnitude of the sum of two vectors is less than the magnitude of either vector, then: a. the scaler product of the vectors

  3. Math

    Find all vectors v in 2 dimensions having ||v ||=5 where the i -component of v is 3i vectors:

  4. Math

    if vectors a+2b and 5a-4b are perpendicular to each other and a and b are unit vectors. Find the angle between a and b.

  1. Physics

    The sum of two vectors of fixed magnitudes has the greatest magnitude when the angle between these two vectors are?

  2. chemistry, polar or nonpolar

    Why is NO3 nonpolar but CIF3 is polar? I looked at the lewis structures, they look similar, but why is one opposite. also, when something is polar or non polar, my teacher said I should see which atom is more electronegativity is

  3. Calculus

    Sketch the vector field F⃗ (r⃗ )=2r⃗ in the plane, where r⃗ =⟨x,y⟩. Select all that apply. A.All the vectors point away from the origin. B. The vectors increase in length as you move away from the origin. C. All the

  4. physics

    the position vectors of the head and tail of radius vectors are 2i+j+k and 2i-3j+k. the linear momomentum is 2i+3j+k. the angular momentum is

  1. Physics

    1) The vector sum of three vectors gives a resultant equal to zero. what can you say about the vectors? 2) Vector is 3.00 units in length and points along the positive x-axis. Vector is 4.00 units in length and points along the

  2. Math - vectors

    For what value of t are these two vectors parallel? a) r = 4i + tj and s = 14i - 12j What I Know: vectors are parallel if one is a scalar multiple of the other. I need to find a way that r and s relate by finding what number you

  3. physics

    A football player runs the pattern given in the drawing by the three displacement vectors , , and . The magnitudes of these vectors are A = 4.00 m, B = 15.0 m, and C = 18.0 m. Using the component method, find the (a) magnitude and

  4. Physics

    The sum & difference of two non-zero vectors Ä & B are equal in magnitude.what can you conclude about these vectors?why?

You can view more similar questions or ask a new question.