+0

# Evaluate inverse trig functions

+10
660
8
+1833

Evaluate inverse trig functions

Feb 4, 2017

#6
+9778
+10

The principal value is

arc cos 0.1 = 84.3°

but also

cos -635.7° ≈ 0.1

cos -275.7° ≈ 0.1

cos 84.3° ≈ 0.1

cos 444.3° ≈ 01

!

Feb 4, 2017

#1
+110153
+10

acos(0.1 = 84.260829522733

Feb 4, 2017
#2
+111438
+10

arcos (0.10)  ≈ 84.3°

Feb 4, 2017
#3
+110153
0

What took you so long Chris

Melody  Feb 4, 2017
#4
+111438
0

Hey...don't get smart with me, young lady......!!!!

Feb 4, 2017
#5
+110153
0

Yes ...   What you going to do about it ??

Melody  Feb 4, 2017
#6
+9778
+10

The principal value is

arc cos 0.1 = 84.3°

but also

cos -635.7° ≈ 0.1

cos -275.7° ≈ 0.1

cos 84.3° ≈ 0.1

cos 444.3° ≈ 01

!

asinus Feb 4, 2017
#7
+8336
+5

The principal value is always between \(0^{\circ} - 90^{\circ}\)

So 84.3\(^{\circ}\) is definitely the correct answer.

Feb 4, 2017
#8
+26004
+5

Agree,   mostly......    the principal value for inverse COS is between  0 and pi/2  (inclusive)  for POSITIVE values of COS.

FWIW.

ElectricPavlov  Feb 4, 2017