If f (x ^ 5) = lgx, then f (2) =?

If f (x ^ 5) = lgx, then f (2) =?

f(x^5)=lgx=lg[(x^5)^(1/5)]
∴f(x)=lg[x^(1/5)]=(lgx)/5
f(2)=(lg2)/5

If lgx + lgY = 2, then the minimum value of 1x + 1y is______ ．

From lgx + lgY = lgxy = 2, we get xy = 102 = 100, X ＞ 0, y ＞ 0, ｜ 1x + 1y = x + YXY ≥ 2xyxy = 2100100 = 15, if and only if x = y is equal sign, then the minimum value of 1x + 1y is 15

If lgx + lgY = 2, then the minimum value of X + y is______ ．

From lgx + lgY = lgxy = 2, we get xy = 102 = 100, and x > 0, Y > 0, then x + y ≥ 2XY = 20. If and only if x = y, we take the equal sign, so the minimum value of X + y is 20, so the answer is 20

If lgx + lgY = 2, then the minimum value of 1x + 1y is______ ．

From lgx + lgY = lgxy = 2, we get xy = 102 = 100, X ＞ 0, y ＞ 0, ｜ 1x + 1y = x + YXY ≥ 2xyxy = 2100100 = 15, if and only if x = y is equal sign, then the minimum value of 1x + 1y is 15