a) Let u=(2,3,-1) and w=(3,-1,p). Given that u is perpendicular to w, find the value of p. b)Let v=(1,q,5). Given that modulus v = sqrt(42), find the possible values of q.
a) u is perpendicular to w, so u • w =0. This means that 23 + 3(-1) + (-1)*p = 0, so 6-3-p=0, hence p=3. b) The magnitude of v = sqrt(12+q2+52) = sqrt(42). Thus, 1+q2+25 = 42, q2=16, so q is either 4 or -4.
CR
Related Maths IB answers
All answers ▸Show that the following system of equations has an infinite number of solutions. x+y+2z = -2; 3x-y+14z=6; x+2y=-5
Solve (sec (x))^2 + 2tan(x) = 0
Let Sn be the sum of the first n terms of the arithmetic series 2+4+6+... . Find (i) S4 ; (ii) S100 .
What is the limit for this function as x approaches 0? y(x)=(cos x)^(1/sin x)