java - Sqrt function invokes an error -

i'm trying aplication calculates equation. need use sqrt errors after trying different metods i've seen on internet. code:

public void calculate(view v){             edittext number1text=(edittext)findviewbyid(r.id.num1text);             edittext number2text=(edittext)findviewbyid(r.id.num2text);             edittext number3text=(edittext)findviewbyid(r.id.num3text);             int num1=integer.parseint(number1text.gettext().tostring());         int num2=integer.parseint(number2text.gettext().tostring());         int num3=integer.parseint(number3text.gettext().tostring());             integer del= num2*num2+4*num1*num3 ;             integer first=-num2-math.sqrt(del)/2*num1 ;   -getting errors here              integer second=-num2+math.sqrt(del)/2*num1 ;  -and here             textview delta=(textview)findviewbyid(r.id.deltatxt);             textview x1=(textview)findviewbyid(r.id.x1txt);             textview x2=(textview)findviewbyid(r.id.x2txt);             delta.settext("delta:"+del.tostring());             x1.settext("x1:"+first.tostring());             x2.settext("x2:"+second.tostring()); 

i have imported java.math.mathcontext , import java.lang.math

you getting type mismatch on these lines understand it:

integer first=-num2-math.sqrt(del)/2*num1 ; integer second=-num2+math.sqrt(del)/2*num1 ; 

the problem because math.sqrt(double a) returns double , trying set result integer.

why assign square root integer anyways?

you can change them doubles, so:

double first=-num2-math.sqrt(del)/2*num1 ; double second=-num2+math.sqrt(del)/2*num1 ; 

---

also, on these lines:

delta.settext("delta:"+del.tostring()); x1.settext("x1:"+first.tostring()); x2.settext("x2:"+second.tostring()); 

you won't allowed use .tostring() on double type. avoid that, remove it. having strings in front of double value display without errors.

delta.settext("delta:" + del); x1.settext("x1:" + first); x2.settext("x2:" + second);