Question

If a, b, c are in AP ; then 2^{ax + 1}, 2^{bx + 1}, 2^{cx + 1}, x ¹ 0 are in –

• A. AP
• B. GP only when x > 0
• C. GP only when x < 0
• D. GP for all x

Answer 1

Answer: (D)

GP for all x

Answer 2

= 2^(b–a)x ; $\frac { \mathrm { T } _ { 3 } } { \mathrm {~T} _ { 2 } }$ = 2^(c–b)x

Now 2^(b–a)x = 2^(c–b)x

̃ 2^{(2b–a–c)x} = 1

clearly x Î R