1.
y=x21−3x43
Step 1: Power rule dxdxn=nxn−1.
dxd(x21)=21x21−1=21x−21
Step 2:
dxd(−3x43)=−3⋅43x43−1=−49x−41
Step 3: Sum the derivatives.
y′=21x−21−49x−41
y' = \dfrac{1{2\sqrt{x}} - \dfrac{9}{4 x^{1/4}}}
2.
y=x−cosx−2sinx
Step 1: dxdx=1, dxd(−cosx)=sinx, dxd(−2sinx)=−2cosx.
Step 2: Sum the derivatives.
y′=1+sinx−2cosx
y' = 1 + \sin x - 2\cos x
3.
y=extanx
Step 1: Product rule dxd(uv)=u′v+uv′, where u=ex, v=tanx.
u′=ex,v′=sec2x
Step 2: Substitute.
y′=extanx+exsec2x
Step 3: Factor.
y′=ex(tanx+sec2x)
y' = e^{x (\tan x + \sec^{2} x)}
4.
y=(lnx)2−4lnx
Step 1: Chain rule for (lnx)2: let u=lnx, dudy=2u, dxdu=x1.
dxd(lnx)2=2lnx⋅x1
Step 2: dxd(−4lnx)=−4⋅x1.
Step 3: Sum.
y′=x2lnx−x4=x2lnx−4
y' = \dfrac{2\ln x - 4{x}}
5.
y=sin(3x+1)
Step 1: Chain rule dxdsinu=cosu⋅u′, u=3x+1, u′=3.
y′=cos(3x+1)⋅3=3cos(3x+1)
y' = 3\cos(3x + 1)
6.
y=ln(secx)
Step 1: Chain rule dxdlnu=u1u′, u=secx, u′=secxtanx.
y′=secx1⋅secxtanx
Step 2: Simplify.
y′=tanx
y' = \tan x
7.
y=(x2+1)5
Step 1: Chain rule dxdu5=5u4u′, u=x2+1, u′=2x.
y′=5(x2+1)4⋅2x=10x(x2+1)4
y' = 10x(x^{2 + 1)^{4}}
8.
y=x2+11
Step 1: Quotient rule dxdvu=v2u′v−uv′, u=1, v=x2+1.
u′=0,v′=2x
Step 2: Substitute.
y′=(x2+1)20⋅(x2+1)−1⋅2x=(x2+1)2−2x
y' = -\dfrac{2x{(x^{2} + 1)^{2}}}
9.
y=[f(x)]−1−h(x)
Step 1: Chain rule for [f(x)]−1: dxdu−1=−u−2u′, u=f(x), u′=f′(x).
dxd[f(x)]−1=−[f(x)]−2f′(x)=−[f(x)]2f′(x)
Step 2: dxd[−h(x)]=−h′(x).
Step 3: Sum.
y′=−[f(x)]2f′(x)−h′(x)
y' = -\dfrac{f'(x){[f(x)]^{2}} - h'(x)}