Find a tangent vector of unit length at the point with the given value of the parameter t. r(t) = (7 + t^2)i + t^2j t = 1

First find the derivative at the given point and later divide by the magnitude of this derivative.

Derivative: r' (t) = 2t i+ 2j t

Magnitude:



Now use the value  t =1

Derivative: 2(1)i + 2(1)j = 2i + 2j
Magnitude: 2√2

Unit vector: [2i + 2j] /[2√2] = (√2)/2 i + (√2)/2 j

Ithink the answer is b : )

February 1848 is when it was added. if that's what you were asking