f(x)=x^4-25x+144, x=1 Find the slope of the tangent line to graph the given value of x
you need to find f'(1), or the derivative of f(x) evaluated at 1. f'(x) = 4x^3 - 25 f'(1) = 4-25 = -21 the slope of the tangent line (which is the slope of the line) at x=1 is -21.
im soo sorry thats thhe wrong problem its : f(x)=x^4-25x^2+144, x=1 Find the slope of the tangent line to graph the given value of x
f'(x) = 4x^3 - 50x f'(1) = 4 - 50 =-46
is -46 y or is it the slope?
its the slope
ok
but where y?
umm, so i gave you the slope to the tangent line, would you like the entire equation of the tangent line? at x = 1, y is... f(1) = 4 - 25 + 144 = 123 the tangent line is of the form y = m*x + b, where m equals the slope, -46. now plug in y = 123 at x = 1 to get b... 123 = -46*1 + b b = 169 the equation of the tangent line is y = -46*x + 169 and y at x = 1 is 123 if you wanted that too
tht should be 120 shouldnt it be?
(1)^4-25(1)^2+144=120
oh yeah, sorry
its cool
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