M(t)M, left parenthesis, t, right parenthesis models the distance (in millions of \text{km}kmstart text, k, m, end text) from Ma

rs to the Sun ttt days after it's at its furthest point. Here, ttt is entered in radians.
M(t) = 21\cos\left(\dfrac{2\pi}{687}t\right) + 228M(t)=21cos(
687
2π
​
t)+228M, left parenthesis, t, right parenthesis, equals, 21, cosine, left parenthesis, start fraction, 2, pi, divided by, 687, end fraction, t, right parenthesis, plus, 228
How many days later does Mars first reach 220220220 million \text{km}kmstart text, k, m, end text from the Sun?
Round your final answer to the nearest whole day.