We'll recall the fact that the derivative of a function at
a given point is represented by the value of the slope of the tangent line at the
curve.
The equation of the tangent line, in the point x =
1 is:
y - f(1) =
f'(1)(x-1)
We'll calculate f(1), by substituting x by 1 in
the expression of the function:
f(1) = 3*1^2 +
1
f(1) = 3 + 1
f(1) =
4
To calculate f'(1), first we'll have to differentiate the
given function with respect to x:
f'(x) = (3x^2 +
1)'
f'(x) = 6x
Now, we'll
replace x by 1 in the expression of the first
derivative:
f'(1) = 6
Now,
we'll substitute f(1) and f'(1) in the expression of the equation of the tangent
line:
y - f(1) = f'(1)(x-1)
y
- 4 = 6(x - 1)
We'll remove the
brackets:
y - 4 = 6x - 6
We'll
add 6 both sides:
y = 6x - 6 +
4
y = 6x - 2
The
equation of the tangent line, to the curve f(x) = 3x^2 + 1, is: y = 6x -
2.
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