ElectricPavlov

What about x =  - 18 ?    x = - 49 ?      ( found graphically)

-2 x^2 -6x -36 =

-2 (x^2+-3x) - 36

-2 (x+1.5)²   + 4.5 - 36

-2 (x+1.5)² - 31.5

I think they are trying to 'hack' around a youtube block that the school might have on their computers    ~ EP

Remember the defintion of sec = 1/cos

so this becomes     cos / ( 1/cos)  - 1/cos * cos

                                    cos^2   - 1        

                                 (1-sin^2)  - 1   =   - sin^2  

Is there anything about who is lying?  ( Like " They all lie?")

(j + 26)  = 3/4 (m-26)

(j-30) = 1/4 ( m+ 30)                solve system of equations to find  j  m 

x distance from the station =    s * t  cos 40                    s = speed  ( in km/min)       t = time (in miutes)

y distance from the station =    7 + s*t sin 40

Using distance formula :

  d² = (s t cos 40)² + (7 + s t sin 40 )²             Given:     s t = 29 * 4 = 116    <===== subst. in and solve for d

Take the derivative with respect to 't'  to find out how fast it is changing at t= 4     <====== can you do that?

Sorry.....   change   'blue'   to  'purple'   ! 

First, use pythag theorem to calculate  XZ

   then   tan x = sqrt(43) / XZ