143k views
5 votes
Which of the following represents vector t=overline PQ in trigonometric form, where P(-5,11) and Q(-16,4) ?

a. t=13.038cos 32.471°i+13.038sin 32.471°j
b. t=13.038cos 212.471°i+13.038sin 212.471°j
c. t=13.038sin 32.471°i+13.038cos 32.471°j
d. t=13.038sin 212.471°i+13.038cos 212.471°j

User Vempo
by
7.9k points

1 Answer

3 votes

Final answer:

To find the trigonometric form of vector \(\overline{PQ}\) between points P(-5,11) and Q(-16,4), one must calculate the vector's components, magnitude, and direction angle. The direction angle must account for the vector being in the third quadrant. The correct trigonometric form is 13.038cos(212.471°)i+13.038sin(212.471°)j.

Step-by-step explanation:

To determine which option represents the vector t=\(\overline{PQ}\) in trigonometric form, where P(-5,11) and Q(-16,4), we first calculate the components of the vector t by subtracting the coordinates of P from Q:

  • tx = Qx - Px = -16 - (-5) = -11
  • ty = Qy - Py = 4 - 11 = -7

The magnitude of vector t can be found using the Pythagorean theorem:

|t| = \(\sqrt{t_{x}^{2} + t_{y}^{2}}\) = \(\sqrt{(-11)^{2} + (-7)^{2}}\) = \(\sqrt{121 + 49}\) = \(\sqrt{170}\) = 13.038

Next, we need to find the direction angle of vector t. The angle θ formed with the positive x-axis can be found using the arctangent function:

θ = tan-1\(\frac{t_{y}}{t_{x}}\) = tan-1\(\frac{-7}{-11}\) = tan-1\(\frac{7}{11}\). After calculation, θ is approximately 32.471°.

Since vector t is in the third quadrant (both x and y components are negative), we must add 180° to θ to obtain the correct direction angle, which is 212.471°.

Now that we have the magnitude and the direction, we can express vector t in trigonometric form as:

t = |t| cos(θ) i + |t| sin(θ) j

In this case, this translates to:

t = 13.038 cos(212.471°) i + 13.038 sin(212.471°) j

The correct option that represents vector t=\(\overline{PQ}\) in trigonometric form is therefore option (b).

User Sjking
by
8.0k points