What is the square root of 91 in radical form?

91^(1/2) or 91^(0.5)

To calculate mechanically. we note that 81^(1/2) = 9 and 100^(1/2) - 10

So the 91^(1/2) is between 9 and 10;

Since '91' is approximately the mid-point between 81 & 100 , then try the mide point of 9 & 10 , which is 9.5

9.5 ^(2) = 90.25

So increase a little bit 90

9.51^2 = 90.440

9.52^(2) = 90.6304

9.54^2 = 91.011 Slightly too large so decrease the decimal

9.539^2 = 90.9925

9.5395^2 = 91.002

So the square root of 91 , to 2 d.p. is 9.5395..

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