In the second and third columns of Table 1, you should see a definite pattern of digits. The last entries in the third column round to `1`, which is the answer to part (b). A similar pattern appears in the cosine columns. Your tool probably reports the last entry as `-0.5times10^(-5)` — very close to `0`, which is the answer to part (c). In part (d), the first fraction on the right-hand side approaches `1`, and the second approaches `0`, so the difference quotient approaches `costext[(]t text[)]` as `Delta t rarr 0`.