Question

Diketahui d (3,-6,1) dan e (m, 4,-2) jika panjang vector de sama dengan 11 , hitunglah nilai m

Answer 1

D(3,-6,1) dan e(m,4,-2)

Panjang, de = 11

Tanya : m = ___?

Jawab :

de^2 = (3 - m)^2 + (-6 - 4)^2 + (1 - (-2))^2

11^2 = (3 - m)^2 + (-10)^2 + (3)^2

121 = (9 - 6m + m^2) + 100 + 9

121 = 9 - 6m + m^2 + 109

0 = m^2 - 6m - 3

(m - 3)^2 = 3 + 9

(m - 3)^2 = 12

m - 3 = akar (12)

m - 3 = +/- 2 akar (3)

m = 3 +/- 2 akar (3)

Ada dua m

m1 = 3 - 2 akar(3)

Atau

m2 = 3 + 2.akar(3)