2.6+day+2

1) A) x^2+z^2=z^2 .64+.25=.16 (.16)^1/2=.4 z=.4 B)2x dx/dt+.25=2z dz/dt 2(.8)+.25=2(1)dz/dt .64+.25=2 dz/dt .445 C)? C) corrected tan (theta)=x/5 tan(theta)=2x sac6a(dtheta/dt)=2(dx/dt) =.4rad/min

checked by Layne Miller

2) B) 10 squareroot 2

Worked by Jason Sham

2) ??? checked by Krissy Denby

3) checked by emily othold

3B) V=pir^2h+4/3pir^3 dv/dt=2pirdr/dt(dh/dt) + 4pir^2dr/dt 261pi= 2pi(3)(2)dh/dt+ 4pi(9)(2) 261pi+2pi(6)dh/dt +72pi 261pi-72pi/(12pi)= 16cm Worked by Elborz Safarzadeh

4) **A**- V= 4/3 pi r^3 dV/dt= 4 pi r^2 10= 4 pi (3)^2 dr/dt= 5/18 pi in/min

A= 4 pi r^2 dr/dt dA/dt= 8 pi r dr/dt dr/dt dA/dt= 8 pi (3) (5/18 pi) dA/dt= 6.667 in^2/min Worked by Michelle Tassin correct! Checked by Rachel Pearce
 * B**-

4C) ?? Checked By Elborz Safarzadeh

5. h=250 dh/dt=5m/sec x=300 b=165.83 250^2 + b^2 = x^2 0 + 2b(db/dt) = 2x(dx/dt) 2b(5) = 2(300)(dx/dt) 2(165.83)5 = 600 (dx/dt) 1658.31 = 600 (dx/dt) 2.764 = dx/dt worked by lauren tinkler checked by Zarion Hilaire correct

6) worked by Jane Swanson [i think this is wong...] um i got the same.. checked by emily othold

7) dD/dt= 20mi/hr when y=0.6 x=0.8 D=1

x^2+0.6=s^2 Deriv: 2x(dx/dt)+0=2s(dD/dt) 2(0.8)dx/dt=2(1)(20) dx/dt= 25mi/hr Worked by Pascal Cuestas checked by sophia Lamay