Question

plz answer the question. que 14​

Answer 1

Answer:

(3^x) +(3^-x) -2=0

let (3^x) = y

let (3^-x) = 1/3^x

let ( 1/3^x ) = 1/y

then y + 1/y - 2 = 0 is equation (1)

y + 1/y - 2 = 0

(y^2 + 1 - 2y) / y = 0

y^2 - 2y + 1 = 0

y = (- b +√ b^2 - 4ac)/2a or ( - b -√ b^2 - 4 AC)/2a

= (-(-2)+√2^2 - 4×1×1)/2×1 or (-(-2)-√2^2 - 4×1×1 )/2×1

= (2 +√4 - 4)/2 or (2 -√ 4 - 4)/2

= (2+0)/2 or (2-0)/2

= 2/2 or 2/2

= 1 or 1

substitute in equation (1)

y = (3^x) = 1

1/y = (1/3^x) = 1

then 1 + 1 - 2 = 0

hence proved