Question 25

ABC is a triangle.
Find as a column vector.
Show clear algebraic working.
Modulus (magnitude) of a vector

ABC is a triangle.
AB=(3−2),BC=(x5x),x>0,∣AC∣=5.
Find AC as a column vector.
Show clear algebraic working.
OX=(2−4) and YX=(6−7)
Calculate the modulus of OY
The position vector of A is (8−3).
The point B has coordinates (2,-4).
Find ∣AB∣.
The vectors
p=(x2x−1),q=(−95)
are such that ∣p∣=∣q∣.
Given that x<0, find the value of x.
Given that
a=(2xx−2)
where ∣a∣=5, find the exact value of x.
The coordinates of point A are (1,8) and the coordinates of point B are (10,-4).

Calculate the modulus of A P.
21OX=(52) and OY=(7−2)
Calculate ∣XY∣, giving your answer as a surd.
The vectors
p=(2x−1y),q=(y+3−y)
are such that ∣p∣=98 and
p+q=(70).
Show that
x2−3x−9=0.
Given that x>0,
Find the exact value of ∣q∣2.
Show your working clearly.

Figure 4
Figure 4 shows a trapezium OACB in which ∠OAC=∠AOB=90∘ so that OB and AC are parallel.
Given that OA=a,OB=b and AC=2b,
Given that ∣a∣=6 cm and ∣b∣=8 cm,
calculate the length, in cm to 3 significant figures, of OP.