Question

Bantu saya kak, Pelajaran Matematika kelas 10

Answer 1

44. Diketahui:

A(4,-2) dan B(3,-1)

AB = p

Ditanyakan: p

Jawab:

AB = p

B - A = p

(3,-1)-(4,-2) = p

(3-4,-1-(-2)) = p

(-1,1) = p

45. Diketahui:

a = i+4j

b = 2i+3j

Ditanyakan:

2a+3b

Jawab:

2a+3b

= 2(i+4j)+3(2i+3j)

= 2i+8j+6i+9j

= 8i+17j

46. Diketahui:

a = (√2 0) dan b = (1 1)

Ditanyakan:

sudut antara a dan b

Jawab:

*|a| = √((√2)²+0²)

= √(2+0)

= √2

*|b| = √(1²+1²)

= √(1+1)

= √2

*cosx = (|a|²+|b|²)/(2.|a||b|)

=((√2)²+(√2)²)/(2(√2)(√2))

= (2+2)/(2.2)

= 4/4

= 1

*x = 0°

47. Diketahui:

a = (4 -2)

b = (0 -1)

Ditanyakan:

3a•2b

Jawab:

3a•2b

= 3(4 -2)•2(0 -1)

= (12 -6)•(0 -2)

= ((12. 0) (-6. -2))

= (0 12)

Mapel: Matematika

Kelas: 10

Materi: Vektor