derivative of 1/(sqrt(64+5t^2))
To ease differentiation, the expression 164 + 5t2 is turned into (64 + 5t2)-12
Let's differentiate: ddt((64 + 5t2)-12)
Apply the differentiation rule: ddt(fn) = n·ddt(f)·fn -1 with f = 64 + 5t2
ⓘ The derivative of x^n is n*x^(n-1): ddt((64 + 5t2)-12) = -12·ddt(64 + 5t2)·(64 + 5t2)-32
-12·ddt(64 + 5t2)·(64 + 5t2)-32
ⓘ Multiplying a fraction by a term multiplies its numerator: -12·ddt(64 + 5t2)·(64 + 5t2)-32 = -1·ddt(64 + 5t2)·(64 + 5t2)-322 = -ddt(64 + 5t2)·(64 + 5t2)-322■The factor is moved to the numerator or the denominator by changing the sign of its exponent, for a nonzero base: -ddt(64 + 5t2)·(64 + 5t2)-322 = -ddt(64 + 5t2)2·(64 + 5t2)32
-ddt(64 + 5t2)2·(64 + 5t2)32
ⓘ The derivative of a sum is the sum of the derivatives: ddt(64 + 5t2) = 0 + ddt(5t2)
-0 + ddt(5t2)2·(64 + 5t2)32
ⓘ Adding 0 changes nothing: 0 + ddt(5t2) = ddt(5t2)■A constant factor stays in front of the derivative, (k*u)' = k*u': ddt(5t2) = 5·ddt(t2)■The derivative of x^n is n*x^(n-1): ddt(t2) = 2t
-5·2t2·(64 + 5t2)32
ⅰ 5·2 = 10
-10t2·(64 + 5t2)32
ⓘ A fraction is simplified by dividing the numerator and the denominator by the same number: -10t2·(64 + 5t2)32 = -5t(64 + 5t2)32
-5t(64 + 5t2)32
▶Derivative:   -5t(5t2 + 64)32