1. Log7 (49)=2
2. Log63(216)=3
3. Log2 (256)=8
4. Log4 (64)= 3
5. Log5 (3125)=5
Answer:
f(x) = sec x. tan x
⇔ f(x) = 1/cosx . cosx/sinx
⇔ f(x) = sin x
+) when f(x) is increasing => sin x increases
=> x will increase
+) f(x) is decreasing => x will decrease
+) f(x) is concave up => x ∈ (-pi/2; 0)
+) f(x) concave down => x ∈ (0; pi/2)
Step-by-step explanation:
Answer:
Equation: r-20=74
Step-by-step explanation:
So he started with 94. I got B
cos4x = cos2x
We know that:
cos2x = 1-2cos^2 x
==> cos4x = 1-2cos^2 (2x)
Now substitute:
==> 1-2cos^2 (2x) = cos2x
==> 2cos^2 (2x) + cos2x - 1 = 0
Now factor:
==> (2cos2x -1)(cos2x + 1) = 0
==> 2cos2x -1 = 0 ==> cos2x =1/2 ==> 2x= pi/3
==> x1= pi/6 , 7pi/6
==> x1= pi/6 + 2npi
==> x2= 7pi/6 + 2npi
==> cos2x = -1 ==> 2x= pi ==> x3 = pi/2 + 2npi.
<span>==> x= { pi/6+2npi, 7pi/6+2npi, pi/2+2npi}</span>
