butuh hari ini ya kk

r =(2t²+4)i + (2t³+5t)j
a) V = dr/dt = (4t)i + (6t²+5)j
t = 2 s —> V = (4.2)i + (6.2²+5)j = 8i + 29 j m/s
b) |V| = √(8²+29²) = √905 m/s
arah : tan θ = 29/8 —> θ = 74,6°