The vertices of the triangle PQR are defined by the position vectors 3. OQ and OR = OP. (a) Find PO, PR. (b) Show that cos RPQ = (7). (c) Find sin RPQ. Hence, find the area of triangle PQR, giving your answer in the form a3.

Respuesta :

Answer:(a) To find the position vectors PO and PR, we need to subtract the position vectors of the vertices P, O, and R.

Given that OQ = OR = OP, we can find the position vector of O by taking the average of OQ and OR.

O = (OQ + OR) / 2

Substituting the values, we get:

O = (3 + 3) / 2 = 6 / 2 = 3

Now, we can find PO and PR by subtracting the position vectors:

PO = P - O

PR = R - P

Substituting the values, we get:

PO = P - 3

PR = R - P

(b) To find cos RPQ, we can use the dot product formula:

cos RPQ = (PQ · PR) / (|PQ| * |PR|)

The dot product of PQ and PR is given by:

PQ · PR = (Q - P) · (R - P)

Substituting the values, we get:

PQ · PR = (3 - P) · (3 - P)

Now, to find cos RPQ, we need to calculate the magnitudes of PQ and PR:

|PQ| = |Q - P|

|PR| = |R - P|

Substituting the values, we get:

|PQ| = |3 - P|

|PR| = |3 - P|

Therefore, cos RPQ = ((3 - P) · (3 - P)) / (|3 - P| * |3 - P|).

(c) To find sin RPQ, we can use the cross product formula:

sin RPQ = |PQ x PR| / (|PQ| * |PR|)

The cross product of PQ and PR is given by:

PQ x PR = (Q - P) x (R - P)

Substituting the values, we get:

PQ x PR = (3 - P) x (3 - P)

Now, to find sin RPQ, we need to calculate the magnitudes of PQ and PR:

|PQ| = |Q - P|

|PR| = |R - P|

Substituting the values, we get:

|PQ| = |3 - P|

|PR| = |3 - P|

Therefore, sin RPQ = |(3 - P) x (3 - P)| / (|3 - P| * |3 - P|).

To find the area of triangle PQR, we can use the formula:

Area = (1/2) * |PQ x PR|

Substituting the values, we get:

Area = (1/2) * |(3 - P) x (3 - P)|

Finally, we can simplify the expression and evaluate the result to obtain the area of triangle PQR in the required form, a3.

Step-by-step explanation: