Answer: 15 is 25% of 60
Step-by-step explanation:
15/.25=60
Answer:
x = 3 and x = -7
Step-by-step explanation:
The given quadratic equation is 
. We need to find the solution of this equation.
If the equation is in the form of 
, then its solutions are given by :
Here, a = 1, b = 4 and c = -21
Plugging all the values in the value of x, such that :
So, the solutions of the quadratic equation are 3 and -7.
Find <span>tan<span>(<span><span>5π</span>12</span>)</span></span> and sin ((5pi)/12)
Answer: <span>±<span>(2±<span>√3</span>)</span>and±<span><span>√<span>2+<span>√3</span></span></span>2</span></span>
Explanation:
Call tan ((5pi/12) = t.
Use trig identity: <span><span>tan2</span>a=<span><span>2<span>tana</span></span><span>1−<span><span>tan2</span>a</span></span></span></span>
<span><span>tan<span>(<span><span>10π</span>12</span>)</span></span>=<span>tan<span>(<span><span>5π</span>6</span>)</span></span>=−<span>1<span>√3</span></span>=<span><span>2t</span><span>1−<span>t2</span></span></span></span>
<span><span>t2</span>−2<span>√3</span>t−1=0</span>
<span>D=<span>d2</span>=<span>b2</span>−4ac=12+4=16</span>--> <span>d=±4</span>
<span>t=<span>tan<span>(<span><span>5π</span>12</span>)</span></span>=<span><span>2<span>√3</span></span>2</span>±<span>42</span>=2±<span>√3</span></span>
Call <span><span>sin<span>(<span><span>5π</span>12</span>)</span></span>=<span>siny</span></span>
Use trig identity: <span><span>cos2</span>a=1−2<span><span>sin2</span>a</span></span>
<span><span>cos<span>(<span><span>10π</span>12</span>)</span></span>=<span>cos<span>(<span><span>5π</span>6</span>)</span></span>=<span><span>−<span>√3</span></span>2</span>=1−2<span><span>sin2</span>y</span></span>
<span><span><span>sin2</span>y</span>=<span><span>2+<span>√3</span></span>4</span></span>
<span><span>siny</span>=<span>sin<span>(<span><span>5π</span>12</span>)</span></span>=±<span><span><span>√<span>2+<span>√3</span></span></span>2</span></span></span>
When you evaluate the function f (x) = 4 • 7 ^ x for x = -1 you get:
f (-1) = 4 * 7 ^ -1
f(-1) = 4* 1/7
f (-1) = 0.5714
The next part of the question is not clear. If it refers to the function at x = 2 then:
f (2) = 4 * 7 ^ (2)
f(2) =4*49
f (2) = 196
If it refers to it in x ^ 2
f (x ^ 2) = 4 * 7 ^ (x ^ 2)
The answer is the second option given
