?
The value of (0.98)3 + (0.02)3 + 3 × 0.98 × 0.02 - 1 = ?
Answer & Solution
Correct Answer:
Option
D
According to question,
(0.98)3 + (0.02)3 + 3 × 0.98 × 0.02 - 1
= (0.98)3 + (0.02)3 + 3 × 0.98 × 0.02(0.98 + 0.02) - 1
= (0.98 + 0.02)3 - 1 [∴ (a + b)3 = a3 + b3 + 3ab(a + b)]
= (1)3 - 1
= 0
Alternate
a = 0.98, b = 0.02, c = -1
a + b + (-c) = 0
So,
a3 + b3 + (-c)3 - 3abc = 0
(0.98)3 + (0.02)3 + 3 × 0.98 × 0.02 - 1
= (0.98)3 + (0.02)3 + 3 × 0.98 × 0.02(0.98 + 0.02) - 1
= (0.98 + 0.02)3 - 1 [∴ (a + b)3 = a3 + b3 + 3ab(a + b)]
= (1)3 - 1
= 0
Alternate
a = 0.98, b = 0.02, c = -1
a + b + (-c) = 0
So,
a3 + b3 + (-c)3 - 3abc = 0
Join the Discussion
Login to post a comment or share your explanation.
Login