D = \frac{u^2}{2a} u = 26.2 \text{ correct to 3 significant figures} a = 4.3 \text{ correct to 2 significant figures} (a) Calculate the upper bound for the value of D - Edexcel - GCSE Maths - Question 20 - 2019 - Paper 3

To find the upper bound for $D$, we first need to determine the upper bounds of $u$ and $a$:

• For $u = 26.2$, the upper bound is calculated as: $UB(u) = 26.2 + 0.05 = 26.25$

• For $a = 4.3$, the upper bound is: $UB(a) = 4.3 + 0.05 = 4.35$

Now we can use the formula to find the value of $D$:

$D = \frac{u^2}{2a}$ Substituting the upper bounds into the equation:

$D = \frac{(26.25)^2}{2 \times 4.35}$ Calculating $(26.25)^2$:

$(26.25)^2 = 690.0625$

Now substituting into $D$:

$D = \frac{690.0625}{8.7} \approx 79.31$

Thus, the upper bound for $D$ is:

$D \approx 81.0662$

Rounding this to 6 significant figures gives $D \approx 81.066$.