Step 1: Find dtdx using the quotient rule.
Given x=1+t21−t2.
Let u=1−t2 and v=1+t2. Then dtdu=−2t and dtdv=2t.
The quotient rule is dtd(vu)=v2u′v−uv′.
dtdx=(1+t2)2(−2t)(1+t2)−(1−t2)(2t)
dtdx=(1+t2)2−2t−2t3−(2t−2t3)
dtdx=(1+t2)2−2t−2t3−2t+2t3
dtdx=(1+t2)2−4t
Step 2: Find dtdy using the quotient rule.
Given y=1+t22t.
Let u=2t and v=1+t2. Then dtdu=2 and dtdv=2t.
dtdy=(1+t2)2(2)(1+t2)−(2t)(2t)
dtdy=(1+t2)22+2t2−4t2
dtdy=(1+t2)22−2t2
dtdy=(1+t2)22(1−t2)
Step 3: Calculate dxdy using the chain rule dxdy=dx/dtdy/dt.
dxdy=(1+t2)2−4t(1+t2)22(1−t2)
dxdy=(1+t2)22(1−t2)⋅−4t(1+t2)2
dxdy=−4t2(1−t2)
dxdy=−2t1−t2
Step 4: Calculate yx.
x=1+t21−t2
y=1+t22t
yx=1+t22t1+t21−t2
yx=1+t21−t2⋅2t1+t2
yx=2t1−t2
Step 5: Substitute dxdy and yx into the expression dxdy+yx.
dxdy+yx=−2t1−t2+2t1−t2
dxdy+yx=0
Thus, it is proven that dxdy+yx=0.
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