Solve for k
k\in \mathrm{R}
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2^{2}+4k^{2}>0
Multiply k and k to get k^{2}.
4+4k^{2}>0
Calculate 2 to the power of 2 and get 4.
k\in \mathrm{R}
The value of the expression 4+4k^{2} is always positive. Inequality holds for k\in \mathrm{R}.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
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y = 3x + 4
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Matrix
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Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
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