Exercise 94 Page 245

Practice makes perfect

a If we call the minimum distance x, we can draw the following diagram.

b To find the minimum distance, which we have labeled x in Part A, we can use the tangent ratio.

tan θ=opposite/adjacent

Let's identify the opposite and adjacent leg to the 11^(∘) angle in our diagram.

Let's solve this equation for x.

tan 11=170/x

LHS * x=RHS* x

x* tan 11=170

.LHS /(tan 11).=.RHS /(tan 11).

x=170/tan 11

Use a calculator

x=874.57418...

Round to nearest integer

x≈ 875

The airplane has to take off at least 875 feet away from the base of the tower in order to clear it including the safety distance.

4.2.1 Sine and Cosine Ratios p.232-234

4.2.2 Selecting a Trig Tool p.237-238

4.2.3 Inverse Trigonometry p.241-242

4.2.4 Trigonometric Applications p.245-247

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