Getting started TI-85/86 calculators, 5
Repeat this process for the other two values in the table below. Only the values
at −27 and x = 8 are exact because only − 27 and 8 of the
x-values are perfect cubes.
x y = 5x
1/3
.
= x y = 5x
1/3
.
=
−27 −15 −30 −15.5361625298
4 7.93700525984 10 10.7721734502
6 9.08560296416 8 10
Exercises
Use your calculator or computer to find the approximate decimal values of the expressions in Exercises T1
through T8. Do not simplify the expressions before entering them and be sure your machine is in radian
mode for the trigonometric f u n ction in Exercise T1. In some cases extra parentheses are needed to express
numerators, denominators, and ex ponents.
1.
O
(a)
√
6 cos(9/7) (b) 6 cos(π/7
3
) ( Edit the expression from part (a).)
2.
O
(−5 − 1.63 × 10
−2
)
−1
3.
O
2 + 8
4 − 6
− 3
5−1
4.
O
A + BC
D
with A = 7, B = 6, C = 5, and D = 4 (Store the values first.)
5.
O
1
2
log
10
(7)
6.
O
1.34 × 10
6
− 4 × 10
5
7.12 × 10
−8
7.
O
√
4 + 7
8−10
8.
O
(−32)
4/5
Outlines of solutions
1a. 0.688885143177 • (If your result is 2.44887304686, your calculator is not in radian mode.) •
Press 2nd
√
6 cos ( 9 ÷ 7 ) to have the screen read
√
6 cos (9/7). Then press
ENTER for the answer.
1b. 5.999748331 • If your last operation was the calculation of
√
6 cos (9/7), press 2nd ENTRY
to put it back on the screen. If you performed other calculations, type
√
6 cos (9/7) again. Press
J until t h e cursor is over the square root sign and press DEL to de let e it. Move the cursor
to the 9 and press 2nd π to replace the 9 with π. Put t he cursor on the close parenthesis and
press 2nd INS . Press ∧ 3 to insert ∧ 3 before the close parenthesis, so the scre en reads
6 cos(π/7 ∧ 3), and press ENTER for the answer.
2. −0.199350118613 • Press ( (−) 5 − 1 . 6 3 EE (−) 2 ) 2nd x
−1
to display
(
–
5 − 1.63e
–
2)
−1
. (A e n stands for A × 10
n
.) Press ENTER for the answer. Notice that (−) is
for negation, − is for subtraction, and x
−1
is for taking reciprocals.
3. −86 • Use ( 2 + 8 ) ÷ ( 4 − 6 ) − 3 ∧ ( 5 − 1 ) to display
(2 + 8)/(4 − 6) − 3 ∧ (5 − 1). Press ENTER for the answer.