ElectricPavlov

I would use cosin rule

c^2  = a^2 + b^2 - 2ab cos c

174^2   =   78^2   +   135^2   -   2 (78)(135) cos c                  solve for cos c     then find  angle measure c   via   arc cos

plug in  t= 1       to find s = displacment = -4 cm

  @       t = 2                  s = +4

So in one second from   1  to 2    displacement   chages by   8           average velocity is   8 cm / 1 sec   = 8 cm/sec

do similar for the other time frames

b.   since it asks for an estimate.....try to estimate the slope of the equation at t= 1

                it is negative  

        it is NEARLY a straight line between  t = .5   (value ~ 3)  to  t = 1   (value = -4)

              slope =     ( 3 - - 4) / (.5 - 1) =  -7/.5 = -14

     approx -14 cm/sec

Here is a desmos graph which ma help you ....

https://www.desmos.com/calculator/fkg8uqs8z0

(x,y)  =  (2 sqrt2 cos pi/12   ,    -  2 sqrt2 sin pi/12 )

302 l     /   ( 9.5 l / 90 sec)  = .........  sec

x = second week

x+24 = first week      summed = $ 86

x        +    x+24 = 86    solve for 'x' the amount in week 2

Similar:

https://web2.0calc.com/questions/help_18545#r1

Similar to you previous post

tan 42 = opp/adj = height / 400

tan 42 = height / 400       solve for height

Tan (angle elev) = opp/adj

                          = 12 / 15

arctan (12/15) = angle elev=.........

According to the tax table above 

.4 (45600 - 43000)  + .2 (43000 - 11 000) = ............   tax

Area A =      6 x (10+18)/2  ft²

Are B = Area C = 4 x 12  ft²

^{You should be able to take it from here !}